Don Hendrix: Mount Wilson and Palomar Observatories Master Optician of Schmidt Cameras and Large Telescopes.
Don Hendrix (1905-1961) was the optician who made the optics for the 48-inch Palomar Schmidt telescope, completed the mirrors for the 200-inch Hale reflector, and made the optics for the Lick Observatory 120-inch Shane reflector. He had begun working in the Pasadena optical shop in 1930, little more than a year before Walter Baade brought the "secret" of the Schmidt camera there from Germany. Hendrix mastered the technique for figuring the required aspheric corrector plates, and made all the Schmidt cameras used in the Mount Wilson Observatory telescopes, beginning with an f/1.8, 2.8-inch one put into use in 1934, and the f/1, 2-inch designed and used by Sinclair Smith in 1935. By the time of his death in 1961, Hendrix had made all the Schmidt cameras used in all the spectrographs on the 60-inch, 100-inch, and 200-inch telescopes, as well as several others for McDonald and Lick Observatories, at least. In all Hendrix made roughly thirty Schmidt cameras of various types. His life, optical career, and several of his Schmidt cameras will be described and illustrated in this paper.
Harold Dennis Taylor, optical designer for T. Cooke & Sons.
H. Dennis Taylor was responsible for several important advances in optical design. He wrote 'The Adjustment & Testing of Telescope Objectives', the most influential book on the subject until modern times. His Photo-Visual objective was probably the first triplet apochromat and was one of the very finest telescopes of any era. Taylor designed the Cooke triplet, possibly the most successful photographic lens of all time, and a highly original and influential design. The first steps towards modern lens coating were taken by Taylor in his work with tarnished lenses. His second book, 'A System of Applied Optics', was an important English language contribution to lens design. The modern style telescope eyepiece is found in an early incarnation in Taylor's works. These and other accomplishments will be discussed.
The tale of two telescopes: the peripatetic history of two Smythian telescopes from the early 19th century to the present.
Within the Astronomy Collection of the Science Museum, London there are two telescopes that although at first glance look unrelated, have a closely linked past that has taken them around the world. The uncovering of their colourful history has throws light on many aspects of the change that has occurred within astronomy from the first half of the 19th century to the present day. They have borne witness to the changes in Physical Astronomy from meridian observation to the measurement of double and variable stars and finally to the rise of photography and spectroscopy heralding the advent of Astrophysics. The career of the telescopes also spans a period during which the whole social environment of British astronomy changed with a gradual move from independent amateurs towards a professional establishment. In many ways the time scale and aspects of these changes differs from that taking place in the rest of Europe and more closely matches the development of astronomy in the United States. Lastly, both these telescopes have borne witness by use, to the rise of scientific expeditions and the steady development of recreational astronomy during their long histories.
Dudley Adams of London: and a typical 4" Gregorian Reflector of his from about 1790.
This paper is a combination 'book review' and detailed description of an example of the work of a well known London instrument maker of the mid to late eighteenth century. The book is a recently published excellent work entitled "Adams of Fleet Street" by John R. Millburn and the instrument is one that I recently acquired and that was made by Dudley Adams in about 1790. There are some interesting details in its construction that indicate the high quality of design and manufacture of that period.
The History of the English Mounting.
The term 'English' Mounting was coined by Sir George Airy in 1844 to describe the form of the Northumberland Equatorial at Cambridge, and to distinguish it from the 'German' mounting. The term has never been particularly closely defined, and some (not the present writer) would apply it to the single ended 'Fork' mounting. The talk will feature in particular the important Shuckburgh telescope, built by Jesse Ramsden at about the same time as, and developed from, the famous Palermo Circle, for Sir George Shuckburgh, Bart., of Shuckburgh, Warwickshire, and also the work of Isaac Fletcher, of Tarn Bank, Cumberland, who collaborated with his brother, using the facilities of the Lowca Ironworks, Whitehaven, Cumberland, to re-design the English mounting in cast iron. The talk will also present as far as possible a complete list of major telescopes built in this form, notably many of the 'carte du ciel' instruments used around the world for that sky survey, and the group of telescopes of about 74" aperture built by Grubb Parsons before and after the Second World War.
John W. Briggs
New insight on Clark mechanics: University of the Pacific's 1884 refractor.
The Alvan Clark and Sons firm built a 6-inch observatory refractor for the College of the Pacific, a Methodist institution, in 1884. The design of the equatorial head appears to be unique among surviving Clark instruments. While the objective lens was lost decades ago, the mechanical parts of this vintage instrument survive in good completeness and condition, with only a few exceptions. Especially interesting are the original weight-driven governor mechanism, the provision for the falling weight, the filar micrometer, and the complete surviving "bright field" illumination system. Well-known California astronomers Heber D. Curtis and Robert G. Aitken used this instrument in their early days; thus the telescope is arguably especially important, given its role as one of California's earliest significant observatory refractors. A historic photograph preserved in Lick Observatory's Shane Archives helps document the few lost components, including the hour-angle setting circle, the falling weight and its cord, and the original pillar, which appears to have been a scaled-up version of those supplied for the 5-inch Transit of Venus refractors of 1874. The College of the Pacific refractor, and the associated 60-mm Fauth transit, are now in the collection of J. W. Briggs and family; and both instruments will be displayed at the Flagstaff ATS meeting.
M. Eugene Rudd.
Joseph Fraunhofer’s First Paper.
In addition to making telescopes, Joseph Fraunhofer made important contributions to the new science of spectroscopy. Many of these were described in a single paper, his first publication. At a time when the wave nature of light was just beginning to be accepted, there was no way to specify positions in the spectrum quantitatively. Fraunhofer solved this problem first by using an array of lamps with a different color of each selected by a prism. In the paper he also described his later discovery of the dark lines in the solar spectrum which provided a more universal set of landmarks in the spectrum. Using these lines, now called Fraunhofer lines, he made highly accurate measurements of the indices of refraction and dispersive powers of several media. These and other achievements have led some to call him the Father of Spectroscopy.
Walter Yund IV.
The Rise and Fall of Dudley Observatory.
In the year 1851, the prominent citizens of Albany, N.Y., established Dudley Observatory. The observatory was planned to be the cornerstone of a university to educate the elite. When the university plans were abandoned, though, the prosperous Albanians supported the observatory out of their own pockets. Within years the observatory was recognized as a first class research facility, and it participated in many scientific studies. The greatest achievement occurred with the establishment of the General Catalogue, which collected the positions and motions of over 35,000 stars. Unfortunately, the observatory's prominence declined as Albany grew. With the loss of interest of the Albany area in astronomy, the observatory was shut down, although a library still operates today. Dudley Observatory's downfall was most unfortunate, as it would have certainly been a prominent institution even today.
Restoring Rachel Part II.
The second phase of restoration of the 20-inch Brashear/Warner & Swasey refractor from Chabot Observatory including installation in the new dome at the Chabot Space & Science Center.
Gary L. Cameron
The Iowa College Goodnow Hall Observatory.
In 1888 Iowa College (now Grinnell College) in Grinnell, Iowa established an astronomical observatory atop Goodnow Hall on the college's campus. This observatory continued in operation until closed in 1928. This presentation describes the author's work in progess researching this facility and its instrumentation including: an 8" Alvan Clark and Sons refractor (1888), a 3" Fauth meridian transit (1890), two Seth Thomas clocks used in conjunction with the transit, and a very rare 6.3" John Brashear Newtonian reflecting telescope (1890). All or part of these instruments still exist in the Grinnell College Collection of Scientific Instruments, an on campus museum.
During the 1800's, a lightly educated, starry-eyed young millwright in Pittsburgh made for himself a 5" lens and a 12" mirror for telescopes he could otherwise not afford. But faced with the exhaustion of long days in the steel mills and sleepless nights working glass in the crawl space under his house, John Brashear was forced to choose between his love of astronomy and his advancing responsibilities in the mill. Gambling that he could make a living selling home-made optics at affordable prices to amateur astronomers, he left the mills and began a career as a telescope and physical instrument maker. By the time of his death four decades later, he was celebrated by scientists around the world who used his instruments to advance the body of knowledge soon to be known as the New Astronomy. Business tycoons, Nobel laureates, civic leaders - all called him "friend", but no group was he more fond of than the common workers of Pittsburgh, who he never neglected. Working tirelessly and with humility recounted as extraordinary in his or any age, there was almost no charitable, educational or civic organization that didn't benefit from his time, reputation or leadership. The story of Uncle John is not just the story of a self made man. His was a life that came to symbolize the best that America had to offer.
Rudi Paul Lindner.
The Lamont-Hussey Refractor
William J. Hussey wanted to erect a large refractor in the southern hemisphere in order to complete the search for double stars he had begun at Lick Observatory. His college friend, Robert P. Lamont, agreed to fund the project in 1908. It should have taken two or three years to build the telescope, but technological deficiencies, war, and the death of James McDowell intervened, and Hussey was not able to test his telescope until 1926. He died en route to set it up in South Africa. This talk is about the design and creation of this, the last great refractor of the classical era.
Flaccus Stifel and Wade Barbin.
The Refurbishing of the Brashear Refractor for AAAP's Wagman Observatory.
In 1986 the Amateur Astronomers Association of Pittsburgh received as donation from Carnegie Mellon University the extant components of an 11 inch John Brashear refractor built for the then titled Carnegie Technical Schools in 1908. AAAP members subsequently refurbished the telescope and installed it at Wagman Observatory in summer of 1995. Wade Barbin and Flacc Stifel will fill in some history and take you through the refurbishment process.
Gottlieb and James W. Fecker.
A very brief overview of the careers of the father & son optical designer / fabricators.
A survey of the major Observatories and Telescopes that the Society has visited over the last ten years.
The Society has deliberately organized its annual meetings at a wide variety of sites so that members have been able to visit as many historic astronomical facilities as possible. Over the last ten years we have covered many important Observatories and there are still many yet to be visited before we begin to make repeat visits. However, it is clear that some sites are so significant in the history of our field of study that we must soon return to them. But the next ten years will probably still be taken up with exploring new ground. This presentation highlights the major instruments that we have visited in the first ten years of our Society.
Optics for the Subaru Telescope.
The fabrication of the optical elements for the 8.3 meter Subaru telescope were accomplished by Brashear L.P. Reviewed will be acquisition of the glass; grinding, polishing, and testing of the several elements.
Trudy E. Bell
The Roles of Lesser-Known American Telescope Makers in 19th-Century American Observatories
While the figure frequently cited for the number of astronomical observatories built in 19th-century America ranges from 142 to 144, the contemporary literature reveals the actual number was well over 200 and may top 250. Fragmentary evidence also exists for perhaps an additional 50 to 100 observatories, although it is not always possible to tell from the literature whether they were permanent structures.
Both the maker and date of completion are known for 424 (82.5 percent) of 514 astronomical instruments built before 1900 - not only large and small telescopes, but also specialty instruments such as transits and meridian circles, and telescope parts such as eyepieces or mounts. More than half of the instruments were built by dozens of lesser-known American telescope makers whose collective accomplishments were eclipsed by the record-breaking fame of Alvan Clark & Sons and of John A. Brashear.
This paper summarizes the work of some of these lesser-known makers, offers some hypotheses for their subsequent obscurity, and outlines plans for a complete directory of 19th-century American observatories and their instruments.
The instruments and methods used at the 1769 transit of Venus.
William Wales and Joseph Dymond were sent by the Royal Society to observe the transit of Venus on June 3, 1769 at Churchill, on the shore of Hudson Bay, where they spent over a year. Nevil Maskelyne, the Astronomer Royal, recommended instruments to be used at the transit and so Wales and Dymond's equipment was typical. It consisted of a pendulum clock by Ellicott, Bird's astronomical quadrant, and two reflecting telescopes by Short, one equipped with an object-glass micrometer. The purpose of this paper is to consider in detail how the instruments were used and how accurate they were.
A new method of measuring chromatic aberration of lenses
M. Eugene and Eric P. Rudd
Measuring the dispersion of glass in the form of a prism is relatively easy and accurate, but when the glass sample is in the form of a lens, it is more difficult and less accurate. It is typically done with discharge tubes (which require a high voltage transformer), narrow-band filters (which are expensive), and a Foucault knife-edge apparatus to find the focal length for different wavelengths (sometimes a tedious job).
Recent improvements in the intensities of light emitting diodes (LEDs) have made a different approach feasible. A new system has been devised and built that uses three inexpensive LEDs of different colors as light sources. They are powered by an inexpensive, low voltage, plug-in transformer. The LEDs are situated behind a single slit so as to produce virtually contiguous illumination of the slit by the three different colors. The slit is imaged by the lens under test. A cardboard mask with two small holes placed next to the lens results in two images of the slit for each color. A small telescope is racked longitudinally to successively bring each image pair into coincidence. The positions for each color are read on a vernier scale giving the differences in focal length. For a lens of a known prescription the tester produced results that agreed well with the expected predictions. Examples of measurements made on several different telescope lenses will be shown.
Reflections on some telescope books.
A presentation on books about telescopes and telescope history, from the owner / publisher / editor behind Willman-Bell books.
An 8 inch Harry Fitz Refractor in a Public School Observatory.
An 8 inch Harry Fitz objective is mounted in a locally made telescope and observatory, that was donated to the local school district and for the past twenty years has been used by students and the public. The history and restoration of the telescope and observatory will be discussed and illustrated.
Gary L Cameron.
Des Moines' Drake Municipal Observatory.
The Drake Municipal Observatory was constructed in the early 1920's in a cooperative effort between Drake University and the city of Des Moines, Iowa as a multi-user facility for students, faculty, and the general public. When opened, the DMO attracted substantial attention from professional astronomers across the United States as well as the general public as one of the first institutions of its kind. The DMO is still in operation and houses an 8.25" Brashear refractor, complete with its original astrograph and guide scope, a 2" Browning meridian transit, and a large collection of glass plates, many taken by the observatory's founder Dr. Daniel Moorhouse.
Robert Royce. Optical Testing in the First Half of the 18th Century.
An overview of testing procedures in this era, concentrating on the first development of the "shop test" for telescope optics. Commentary will largely include the work of Hadley as given in Smith's Opticks with inclusion of supposition of other tests. Materials will include actual reconstruction of Hadley's test and comparison with descriptions in Smith's Opticks.
"Two Challenge Questions: 1) Largest Clark Optics? 2) Largest Refractor Seriously Proposed?"
For all the fame of the Clark firm, details of their largest known optics remain surprisingly obscure and even controversial. We shall review aspects of this history, and, in passing, touch upon a serious but now obscure discussion of the largest refractor ever proposed.
Peter Abrahams and Victor Lopez.
The Observatory of Bogota, Colombia, founded 1803.
The first observatory in the Americas can be traced back to temporary buildings used in the 1630s. The first permanent, dedicated structure designed for use with a telescope is likely the observatory of Bogota, Colombia. This beautiful tower housed a variety of significant instruments and stands to this day as an icon of Colombian history.
MEETING OF THE ANTIQUE TELESCOPE SOCIETY, SEPTEMBER 2002
ABSTRACTS OF PRESENTATIONS TO THE SESSIONS
The Six Foot Rosse Telescope.
An overview of the design, fabrication, and use of the Rosse telescope. Restoration efforts beginning in 1994 were researched and engineered by Tubridy, and the laborious reconstruction of the deteriorated instrument will be described in this presentation.
The History of the ATS in Slides.
The ten annual meetings of the Antique Telescope Society have been sited at leading observatories in North America and England. The many memorable telescopes that have been part of our meetings will be highlighted.
H. Dennis Taylor, the Cooke Triplet Lens and the Victorian Patent System.
H. Dennis Taylor (1862-1943) worked for the Yorkshire optical firm of T. Cooke & Sons as their optical manager. In the 1890s, he designed and patented a novel compound lens system having three elements, which is the origin of the apochromatic telescope objective lens. Cooke & Sons did not want to manufacture the design, but Taylor was able to persuade Taylor, Taylor & Hobson of Leicester (no relation) to manufacture it instead. Out of deference to H.D. Taylor's employer, however, the design was sold as the Cooke triplet lens. This paper briefly reviews the different aberrations which may be present in lens systems, the great signficance of Taylor's new design in overcoming them, as well as its historical context.
The Telescope Collection of The Science Museum, London.
The Science Museum in London maintains one of the foremost collections of telescopes in the world. This presentation will show and discuss some of the highlights of the collection.
The heliometer. Its development in the 18th and 19th century and its contribution to our astronomical knowledge.
Part I: 18th century.
Part II: 19th century.
The heliometer, whose invention goes back to the first half of the eighteenth century, was in astronomy the classic instrument for distance measuring, the so called "parallax measurement". First improved by John Dollond, it allowed in 1769, during the transit of Venus across the sun, the determination of the solar parallax with the highest accuracy ever made. Further improved by Peter Dollond, it reached toward the end of the century the highest level which was possible with eighteenth century optics and mechanics. After a stop in development of nearly 30 years, it was further improved by Josef Fraunhofer. The first successful determination of the parallax of a fixed star by Bessel was a further proof of the still not exhausted possibilities of that instrument. Toward the middle and in the second half of the nineteenth century, the Hamburg firm A. and G. Repsold improved the heliometer to such a perfection, that astronomical distance measurements, from several hundred millions of kilometers in the eighteenth century, reached to the enormous extent of many thousands of light years.
The Telescope in Ireland: Obscure makers & marks. Irish telescope makers and Irish signatures on telescopes.
An annotated list of names found on telescopes made or sold in Ireland. The primary purpose of this list is to identify Irish telescope makers. A secondary purpose is to provide information about inscriptions found on telescopes, to assist in the documentation of telescopes in collections, and therefore some of these names are retailers only.
Edward J. Young.
The Great Melbourne Telescope: An Irish Connection.
In 1838 Sir John Herschel returned to England after four years observing nebulae from the Cape of Good Hope with a 19-inch, 20-foot focal length reflector. The idea of permanently placing a large aperture telescope in the Southern Hemisphere was first raised around 1840. The driving force behind this initiative was Romney Robinson, Director of Armagh Observatory. Robinson was a brilliant mathematician with an encyclopedic mind. He was also described as "a pugnacious Irishman with an unbridled enthusiasm for all things Irish". From the outset, Robinson determined that a great southern telescope would be an Irish project. The first proposal to the Treasury to fund the project was denied in 1849. Undeterred, Robinson contracted with Thomas Grubb, an engineer with the Bank of Ireland, to draw up plans for an equatorial mounted reflector of 48-inch diameter. The project was resurrected in 1852 at the Belfast meeting of the British Association, and had it not been for the outbreak of the Crimean War, it might have been funded. The project resurfaced again in 1862 when the territory of Victoria in Australia approached the Royal Society for assistance with a large telescope. When they agreed to fund the entire project, Melbourne replaced the Cape as the site for a great reflector. At Robinson’s urging, a traditional speculum metal mirror won out over the silver-on-glass technique that was gaining popularity on the Continent. When the Great Melbourne Telescope went into operation in 1869 it was not only the biggest equatorial telescope in the world, but also the largest and most expensive piece of scientific apparatus in Australia. Unfortunately, the great reflector did not fulfil the promise of its creators, and by 1893 was withdrawn from service. Parts of the Great Melbourne Telescope were resurrected after World War II at Mount Stromlo Observatory and thereafter, twice refurbished and rebuilt, it continues in service today. Although some believe that the major fault lay with the speculum mirror, the real problem was that the telescope was designed for visual observations and hand drawings of nebulae. The telescope proved ill suited for photography and spectroscopy; techniques that revolutionized astronomy after the 1870s.
The Crawford Observatory, University College Cork, Ireland.
This tiny little observatory houses a veritable museum of 19th century Grubb telescopes and other instruments. Some of these instruments, and indeed the buildings themselves, incorporated innovations to keep pace with the changing demands of astronomers. Many of the instruments never did much practical work, have remained intact for 120 years, and are very well preserved. This paper describes the observatory and contents.
Photographs of optical processing methods developed at Grubb Parsons and later at Sinden Optical Co.
The chief optician for Grubb Parsons will present an evening of slides and informal discussion on the products and techniques of these two companies.
When an Eye is armed with a Telescope: The Dioptrics of William and Samuel Molyneux.
William and Samuel Molyneux of Dublin were father and son scientists who made significant contributions to the development of the telescope in the late 17th and early 18th centuries. William wrote the first English language book on technical optics, the 'Dioptrica Nova'. Samuel wrote and edited the most extensive English language instructions on fabricating reflecting telescopes, consisting of three chapters in Robert Smith's 'Compleat System of Opticks'. Their correspondence, travels, and influence make an interesting portrait of the instrumental astronomy of their time.
Grubbs Are Good For You.
A veteran operator of the Armagh Observatory ten inch Grubb refractor of 1884 will relate his experiences "using the telescope the way it was originally meant to be used, i.e. visually, with no more than the addition of a micrometer".
'Lets Find Out': Some notes on Grubb's Lens Making methods.
Sir Charles Parsons had a saying: "I don't know, and you don't know, so - Lets find out." This talk will delve into and study the work of past masters including Bill Latimer, who was Sir Howard Grubb's top optical worker for many years, and also worked in Newcastle for Sir Charles Parsons.
A Collection of Instruments made and used by A. E. Douglass.
Andrew Ellicott Douglass (1867-1962) was one of America’s great men of science. Primarily an astronomer, Douglass’s interests were wide-ranging and voracious. In addition to helping establish four American observatories, Douglass made substantial contributions to the fields of climatology and archaeology and established the field of dendrochronology. In 1901, he became intrigued with the growth rings visible in the trunks of trees. Speculating that they might indicate a relation between solar variation and terrestrial climate, Douglass designed and created a number of increasingly complex instruments to help him study cycles. His research helped him establish a chronology that enabled the prehistoric Pueblo ruins of the American Southwest to be accurately dated. The University of Arizona, where Douglass worked for more than fifty years, has preserved a number of these instruments, and my paper will describe them and discuss their significance. Douglass filmed various foreign astronomical observatories in 1931, and a narration of his photography will be included.
James Nasmyth: Ironmaster & Astronomer.
James Nasmyth is probably best remembered by historians as a successful Victorian industrial entrepreneur who invented the steam hammer. Despite this footnote in history, Nasmyth spent the latter part of his long life pursuing his keen interest in astronomy. Using his skills and the facilities of his engineering works at Patricroft near Manchester, he constructed several large telescopes to study the Sun and Moon. His largest telescope, a 20-inch reflector was notable for its tertiary mirror configuration, which allowed the observer to remain seated while the telescope moved. This arrangement that now bears Nasmyth's name, is to found on most of the new generation of large altazimuth mounted telescopes currently being built. Nasmyth made his most notable contributions through his extensive studies of the Moon and the resulting book that he jointly published with James Carpenter in 1871. It was lavishly illustrated with real photographs of his plaster model of the lunar surface illuminated at varying angles. He found that these gave a more realistic impression of the lunar surface than could be achieved with direct lunar photography at the time.
The life and work of Nasmyth can be gauged from of his surviving instruments, drawings, paintings and photographs. The majority of these are held by the Science Museum, London and form a unique archive of Nasmyth's work.
The Astroscope by James Mann: the first commercial Achromatic Refracting Telescope c.1735 ?
An unusual variation on the telescope, by a leading instrument maker.
New Light on early Chinese Telescope Making.
The history of the telescope in Asia, generally, and China in particular, is not well studied or recorded. Yale University library owns a 1966 Taiwanese reprint of an early Chinese text containing information about the telescope. This text, figuratively entitled "A Fascinating Treatise about Telescope Making" by Uan Shiang and Jun Fu Guong, was originally published in 1848, under the rule of Emperor Dou Guong in the Ching Dynasty. A cursory study of this work offers us some interesting insights regarding the level of interest, knowledge and enterprise in telescope making achieved by a few intellectual Chinese artisans during this period.
The Palermo Ramsden Circle and the Dunsink Meridian Circle: possible connections.
The Palermo Circle and the Dunsink Circle are the largest circular-scale instruments designed by the well-known British instrument-maker Jesse Ramsden (1735-1800). The Dunsink Circle was ordered before the Palermo Circle but completed much later. It is interesting therefore to remark the analogies and the differences between the two instruments in order to understand how their construction was carried out and if their design influenced each other. This analysis will be eventually completed by a brief history of the two instruments and their utilization.
Peter Louwman and Rolf Willach.
Photographs of signed telescopes from the early 17th century into the 19th century, with discussion on the makers and manufacturing techniques.
The majority of the earliest telescopes were not signed. Examples that carry a signature will be shown and discussed, emphasizing the criteria for establishing age, the development of manufacturing techniques, and the body of knowledge about the individuals and shops represented by the various signatures.
MEETING OF THE ANTIQUE TELESCOPE SOCIETY, SEPTEMBER 2003
ABSTRACTS OF PRESENTATIONS TO THE SESSIONS
Cook, Green, Solander and the 1769 transit of Venus.
By the time of the two eighteenth century transits of Venus it was realised that precise measurements of these rare events could potentially reveal the solar parallax and hence one of the fundamental yardsticks of international astronomy, the astronomical unit. This led in 1761 to what has been described as "… the first international scientific enterprise undertaken on a global scale …", and more than sixty observing stations were established by teams from a dozen different countries. However, the overall results proved inconclusive, and the focus shifted to the 1769 transit.
For this transit, the British mounted an ambitious program, and observing parties were dispatched to Cornwall in England, North Cape in Norway, Hudson Bay in Canada and newly-discovered Tahiti in the Pacific. Lieutenant James Cook was in charge of the expedition to Tahiti, ably assisted by Green, Solander, and eight others, located at three different observing sites. Their observations contributed significantly to the value of the solar parallax subsequently announced by Hornsby.
In this paper we will sketch out the biographies of Cook, Green and Solander, examine their telescopes and other astronomical equipment, follow their observations of the transit, and describe their ultimate results. We will conclude by briefly reviewing nineteenth and twentieth century methods employed to refine the value of the solar parallax, before discussing the up-coming 2004 and 2012 transits.
Donald E. Osterbrock.
Frank E. Ross, His Ross Lens, and the Lick Observatory 20-inch Astrograph.
Frank Ross invented or designed his wide-angle lens while he was at the Eastman Kodak Research Laboratory from about 1916 to 1924. The lens was intended for use in aerial photography in World War I, and Ross published its basic design as a "wide-angle astronomical doublet" in 1921. In his paper he gave the design for an f/8 lens of 6-inch aperture; his own contribution was to calculate the surfaces and separations to remove field curvature and reduce astigmatism from the previously used Cooke triplets. Ross stated that his type of lens would be most useful in astronomy at f/7, because of its speed and small images.
The first ones used, however, were much longer focus, a 6-inch f/30 ordered for the coude spectrograph of the new 100-inch Mount Wilson reflector in 1922, and a pair of 4-inch f/15's used by W. W. Campbell and R. J. Trumpler of Lick Observatory at the Wallal, Australia eclipse that same year.
After Ross moved to Yerkes Observatory in 1924 he had first a pair of 3-inch examples made (photographic and photovisual), for photgraphic photometry and nebular photography, and then a 5-inch. G. W. Cook had a 4-inch and then a 10-inch made, which went into use in 1938 on a Milky Way program at his observatory outside Philadelphia. The culmination of this series was the Lick 20-inch astrograph, built for its proper-motion program conceived by Ross's close friend William H. Wright. It finally was put into operation in 1947 by C. D. Shane and his assistant Carl Wirtanen. Nearly all these Ross lenses were made by J. W. Fecker at Pittsburgh.
History of the 'Catts Telescope': a nineteenth century 20-inch Grubb reflector.
The name of 'Grubb' is well-known in astronomical circles, and is associated with a number of famous nineteenth and twentieth century telescopes. In Victorian Telescope Makers. The Lives and Letters of Thomas and Howard Grubb (Institute of Physics, 1997), Ian Glass provides a master list of known Grubb telescopes, but missing is a 20-in (50.8-cm) f4.5 Cassegrainian reflector that was manufactured towards the end of the nineteenth century. Known colloquially in Australia as the 'Catts Telescope', this research-class instrument was enjoyed by a succession of British and Australian amateur astronomers until it was purchased by Mount Stromlo Observatory in 1952.
Initially it was used for variable star photometry, until larger instruments were acquired, and was then furnished with a 66-cm mirror and relocated to Mount Bingar during the site-testing program that led to the establishment of the Siding Spring outstation. Apart from its sky-monitoring role, while at Mount Bingar the Catts Telescope was also used for photometric and spectrophotometric research by staff and post-graduate students.
When Mount Bingar was closed in 1963 the Catts Telescope became surplus to requirements and was offered—minus the optics—to the University of Western Australia. Replete with a new 41-cm primary, the refurbished telescope was installed at Perth Observatory and used intermittently for variable star photometry until the dome was required for other purposes in 1998.
After briefly reviewing the successive amateur owners of this century-old telescope, I will discuss the various research programs with which it was associated at Mount Stromlo, Mount Bingar and Perth Observatory.
Trudy E. Bell.
Private Observatories in the 19th-Century United States: A Progress Report.
A detailed analysis of 19th-century U.S. astronomical literature between 1840 and 1900 reveals evidence of at least 40 privately-owned, permanent astronomical observatories (permanently mounted telescopes in dedicated buildings) plus at least 90 additional possible observatories (instruments are documented, with some uncertainty about their status of being fixed in dedicated buildings). This is a substantial fraction of the total number of U.S. observatories documented over the same period (estimated between 140 and 200).
Although most private observatories housed moderate-sized instruments, a few housed refractors up to at least 16 inches in diameter and silver-on-glass reflectors up to 22 inches (in an era when the largest professional institutions housed refractors up to 40 inches in diameter and reflectors up to 36 inches in diameter). The instruments were made by a wide variety of U.S. and European instrument makers as well as sometimes by the observatory owner’s own hands.
What did these private observatories look like? Who were the owners? How much did they spend for their facilities? What astronomical work did they pursue? Although images are rare, this preliminary census reveals much of interest about 19th-century amateur and recreational astronomy as well as about the availability of astronomical instrumentation outside of schools and major research institutions. (This research is a subset of a long-range goal of compiling a complete census of 19th-century U.S. observatories.)
Wayne Orchiston, Nha Il-Seong, Juergen Hamel, Kevin Johnson, Tsuko Nakamura, & Sara Schechner.
Documenting and preserving our international astronomical heritage: the IAU Historical Instruments Working Group.
With the passing of the years more and more of our astronomical heritage is lost to us as old telescope and other historically-important instruments are destroyed, vandalised, or simply loose their fight against the passage of the years and disintegrate. In order to help identify, document and preserve surviving instruments of historical significance the International Astronomical Union formed an Historic Instruments Working Group at the 2000 General Assembly in Manchester. This is chaired by the distinguished Korean historian of astronomy, Professor Nha Il-Seong.
The objectives of the Working Group are
--To assemble a world check-list of extant historically-significant astronomical instruments of all kinds
--To assemble a list of existing publications relating to such instruments
--To encourage colleagues to carry out research on historically-significant astronomical instruments and to publish their results
We invite ATS members to join this Working Group and participate in these projects—there is no need to be an IAU member. The obvious starting point for the first of the above objectives is to prepare inventories for individual institutions (such as observatories, museums, science centres and planetariums) and private collections, and to then grow these into national inventories.
In this paper we will explain the different types of instruments studied, criteria used to identify ‘historical significance’, and the Working Group’s database and web site, before discussing ways in which ATS members can become involved in this exciting international project.
Thomas Dobbins & William Sheehan.
William Henry Pickering and the Egg-Moons of Jupiter.
Harvard astronomer William Henry Pickering (1858-1938) maintained that Jupiter's Galilean satellites are slowly tumbling elliptical swarms of dust rather than monolithic spherical bodies. Possible sources of this illusion are discussed and tube currents are proposed as a solution.
Bradley E. Schaefer.
Visibility Through Old Refractors of Phobos & Deimos, Venus Black Drops, Mars Craters, Sunspots, and the Pup Star.
The heroic days of visual observers making great discoveries through antique refractors are essentially long gone. As historians we can try to understand the limitations and capabilities of their telescopes, while as modern observers we can try to repeat their feats. I have been working on a long-term program of calculating the visibility of objects in the sky, and this frequently has utility for understanding the old discoveries. I'll discuss the results for five of the great results from history as made through old refractors:
(1) Asaph Hall discovered Phobos and Deimos with the USNO refractor, and this can be repeated with a fairly small telescope during Mars' currently very favorable opposition.
(2) The Black Drop during Venus Transits killed the utility of the great expeditions of the 1700's and 1800's, with the root cause being the small aperture and relatively poor optics of the early refractors.
(3) Did Mellish see the Martian craters?
(4) The Zurich sunspot count still stands as the much-used cornerstone of modern Sun-Earth connections, yet the observations with the standard refractor in Zurich have a fatal flaw that is a just-revealed scandal.
(5) The Pup Star around Sirius was a great discovery by Alvan Clark which first revealed the dilemma on the nature of a white dwarf.
The Early Use of Filters in Visual Astronomy.
Filters or 'screens' have been used since the earliest days of the telescope, for purposes including the reduction of excessive light, the elimination of spurious color, and the increase of contrast in the image.
Thomas Dobbins & William Sheehan.
Canals and Craters: Mars and the Limits of Telescopic Vision.
Lessons are drawn from the canal controversy that raged a century ago regarding resolving power of telescopes on extended objects like planetary markings, particularly linear features. The current debate over purported historical sightings of Martian craters is reviewed and the notion that Martian craters can be observed with Earth-based telescopes is refuted.
After The Restoration: Care of Antique Scientific Instrument Collections.
The ultimate intent of collectors of antique scientific instruments, be they amateur collectors or museum professionals, is the preservation of artifacts. Preservation does not require that an object never be used, simply that it be intelligently handled and stored when not in use. This presentation will briefly cover some basic principles of conservation and preservation of metals, glass, wood, paper, and other materials encountered by the telescope collector; and includes suggestions for safe handling and storage. Sources of supplies for archivally safe storage materials will also be discussed.
Some personal thoughts on and methods of optics cleaning, and in search of the perfect lens brush.
Methods I have used over the years for cleaning optical surfaces, including strip coatings and a water method.
The restoration of Maria Mitchell's Dollond refractor, and further adventures of an itinerant celestial mechanic.
The Maria Mitchell Dollond is the oldest telescope restored by Chris Ray. Further work in progress will be illustrated.
MEETING OF THE ANTIQUE TELESCOPE SOCIETY, SEPTEMBER 2004
ABSTRACTS OF PRESENTATIONS TO THE SESSIONS
Jascin N. Leonardo Finger.
The Mitchells Good: Maria Mitchell, the Mitchell Family and the Nantucket Maria Mitchell Association.
Maria Mitchell, born on Nantucket in 1818, became America’s first woman astronomer and the first female professor of astronomy in the United States at Vassar Women’s College in 1865. The unique environment in which she grew up and her Quaker upbringing afforded Mitchell many opportunities that other young girls and women did not have at that time. Her unique family helped to foster Mitchell’s beliefs, interest in the sciences and education as well as her life-long love of learning. Ms. Leonardo Finger will outline the life of Maria Mitchell as well as highlight information about the entire Mitchell family, the House in which they lived - which has been a museum for over 100 years - and the Nantucket Maria Mitchell Association founded in 1902.
Paul A. Valleli.
On an Optical Investigation of the Maria Mitchell Observatory Astrograph.
The classic 7-inch Cooke F/4.5 Triplet designed by H. Dennis Taylor began operation in 1910 and continued to the 1990's, when Kodak discontinued the supply of 8X10 glass plates. Much research was done on the stars in the Scutum star cloud and later as a teaching tool for students considering a career in astronomy.
Taylor had suggested that the central optical element could be oriented for high resolution at the center of the field of view or reversed to minimize blur circle size across the entire field. Margaret Harwood, first Director of MMO, tried both orientations several times but was unsure which was best. Dr. Dorritt Hoffleit, 2nd Director, was less concerned, but Dr. Lee Belserene, the 3rd Director, had come from Lick Observatory where their modern astrographs routinely recorded 5 micron diameter star images. Dr. Belserene enlisted the author on a volunteer basis to perform an exhaustive study of the lens assembly with design assistance from Dr. James G. Baker of the Harvard-Smithsonian staff.
During the reverse engineering process, the lens was fully characterized and some interesting discoveries were made about Taylor's design/fabrication abilities. The lens was re-spaced for improved performance. Dr. Baker showed that much better images could be obtained by aspherizing the first and third lens, however, it was decided not to take the risk that an element might be broken in the process.
The Early History of an Old Wood Tube Clark and Some Thoughts on Wood Tube Construction and Care.
This program will discuss the early history of on old unsigned, wood tube Clark refractor which may be one of the best documented of the very early Clark instruments. Early photos of the telescope will be shown along with some of the 19th and early 20th century astronomers who used this scope. I will speculate as to when this scope might have been made, showing evidentiary features. Lastly, the presentation will deal with the disadvantages of using wood for telescope tube construction, how some of these early tubes were constructed, and some points on caring for an old wooden telescope tube.
Restoring a 1922 Clark 10.5 inch refractor clock drive, and notes on the wood tube 5 inch Clark at MMA.
The five inch Clark refractor at Maria Mitchell Observatory, made in 1859, was recently restored by Chris Ray. The cracked wooden tube was repaired, missing parts were fabricated, and the objective lens subjected to testing.
Another recent restoration was the clock drive for the mount of a 10.5 inch Clark refractor. Technical drawings were drafted and gears calculated, with extensive records kept for future work.
Craig B. Waff and Trudy E. Bell.
Alvan Clark's Pre-Factory Period, 1847-1859: New Information from Recently Discovered Documents
Hitherto unexamined documents (full transcriptions of which are slated to be published in issue no. 27 of JATS) provide new details regarding Alvan Clark's telescope-making activities in the period prior to 1860, when he was struggling to establish a reputation as a professional optician and maker of telescopes of outstanding quality, after earlier careers as an engraver and portrait painter. The documents that we and other researchers have recently discovered include letters of Clark written to Boston newspaper editors, news articles about him in early issues of Scientific American, and his personal correspondence with Elias Loomis, the major contemporary chronicler of mid-19th-century American astronomy. In this paper we recall our adventures this past summer in discovering these documents, reconstruct some of the important events in Clark's pre-factory career, and suggest new lines of research that may further increase our knowledge of Clark and his work during the pre-factory period beyond that provided in Warner and Ariail’s Alvan Clark & Sons: Artists in Optics (1996).
Craig B. Waff.
Alvan Clark's Struggle to Establish His Optical Reputation, 1847-1849.
As a follow-up to the preceding paper, I examine in detail the four letters that Clark sent to the Boston Courier in 1847-1849, in which he discussed the construction and testing of, and initial observations with, the first refracting telescopes that he constructed.
Trudy E. Bell.
'A Hell of a Hole': The Nearly-Forgotten San Luis Southern Observing Station of the Dudley Observatory.
The Dudley Observatory in Albany, N.Y., built and operated a southern observing station at San Luis, Argentina 1909–1911, measuring star positions with Dudley’s own 8-inch Olcott Meridian Circle. At its peak, the San Luis Observatory had a staff of 10 observers (larger than Dudley itself), who set a world record of measuring some 87,000 transits of stars across the meridian in less than 22 months. Fueling that breakneck speed, however, were the grueling physical conditions under which the men labored and from which they longed to be freed, to the extent that they unilaterally omitted all of the photometry originally planned so as to leave a year early—a story barely hinted at in the sparse secondary literature so far published about the San Luis Observatory but fully revealed in some 2,000 pages of unpublished correspondence in the archives of the Dudley and Lick observatories and the Carnegie Institution of Washington. The presentation will recount the grand astrophysical goal of extending positional astronomy to the southern skies, describe the construction of the temporary observatory (including the feat of dismounting, shipping, and re-erecting the largest meridian circle in the world in the southern hemisphere, plus installing the separate photometry telescope, chronographs, and clocks), and detail the astronomers’ nightly and daily tasks in accomplishing their mission. Lastly, it will analyze the effects of continual physical stress on their behaviors in the context of recent literature about the psychology of isolation and confinement in polar and space expeditions—an approach that also may illuminate more famous examples of staff dissension (such as that at the early Lick Observatory).
George W. Ritchey: A Visual Tour of His Contributions to Astrophysics.
I was fortunate to have acquired the George W. Ritchey collection and now feel compelled to spread the word of Ritchey's enormous contributions to early 20th century astrophysics. During my presentation, I will act as little more than a tour guide as you gain a visual overview of many of Ritchey's major technical accomplishments as seen through original period imagery gleaned from his personal archive.
The Telescope in Japan, 1600-1900
Long before the birth of modern Japanese telescopes, there was a tradition in Japan of craftsman fabrication of highly decorative small telescopes. European telescopes were introduced to Japan in 1613, and within a decade, a telescope had been fabricated. Production in quantities began circa 1800, with small refractors by Zenbei Iwahashi and Gregorians by Kunitomo Tobei. Craftsmanship was developed ab initio; involving materials such as quartz, optical glass, and speculum metal; and processes of precision metal fabrication. A few observatories were constructed for telescopic astronomy. Solar observations and instruments are also part of the record.
Many photographs of these early instruments were obtained in a recent tour of Japan and will be shown and described. The gilt decorations and elaborate fittings found on these telescopes are quite beautiful and are unlike other early telescopes.
Textual evidence includes recorded observations of astronomical phenomena, and descriptions of military and surveillance use. A complicated series of prohibitions and restrictions were enacted in response to the telescope. Secrecy and control were part of the assimilation process. In addition, the telescope was depicted in the Japanese literature of the same era, in imaginative and interesting contexts, and as symbolic of human characteristics.
The assimilation of Western instruments and Western science into the isolated culture of Japan was accomplished with much resistance, intricate regulation, and surprising artistic expression.
MEETING OF THE ANTIQUE TELESCOPE SOCIETY, OCTOBER 2005
ABSTRACTS OF PRESENTATIONS TO THE SESSIONS
Craig B. Waff.
“One of the greatest triumphs of theoretical Astronomy”: New Insights Regarding the Mathematical Prediction and Discovery of the Planet Neptune.
Over the last 160 years the events surrounding the dramatic discovery of the planet Neptune on 23 September 1846 have been recounted many times, in articles, book chapters, textbook sidebars, and now even a multitude of Web sites. Most such accounts, however, rely primarily on the relatively small collection of documents presented by the British Astronomer Royal George Biddell Airy at the 13 November 1846 meeting of the Royal Astronomical Society and subsequently printed in the society’s Monthly Notices and Memoirs. Not surprisingly, these documents reflect Airy’s personal view of the Neptune episode. Over the last 50 years, however, a more balanced interpretation has emerged as various scholars have uncovered additional relevant documents in various archival collections in England, France, Germany, and the United States. Most dramatically, the actual collection of Neptune documents assembled by Airy, far larger than the printed collection, was recovered in 1998 after being “missing” for more than 30 years. This recovery impelled Nicholas Kollerstrom (affiliated with University College London) and me to search for and transcribe all documents, especially letters and news accounts, relevant to the discovery of Neptune, with the goal of publishing them, with annotations, in a print edition and/or on the Web. Tonight, I shall present a sampling of these documents, plus some of the new insights that we have so far gained from studying them.
M. Eugene Rudd.
Dioptrice: A Project to Study Early Refracting Telescopes. (M. Eugene Rudd, Duane H. Jaecks, and Marvin Bolt)
The authors have embarked upon a project to make an optical study of the hand telescope during the first two centuries after its invention. We hope to gather data from a large enough number of telescopes to enable us to learn something about their development and usage and to identify characteristics of different eras, different countries, and different makers. We have begun with a study of the early telescopes at the Adler Planetarium and Astronomy Museum and have received grant funding from the National Endowment for the Humanities to continue such work by examining instruments at Harvard University and at the Smithsonian Institution. Data and photographs will eventually be presented on the Adler web site.
The Enigmatic History of the First Curved Plate Cameras.
At the turn of the 20th Century, Frank L. O. Wadsworth designed a radically new Astrographic Camera to overcome the nagging problem of field curvature in wide field imaging. Utilizing the talents of Brashear, Hastings, McDowell and several glass industry experts, at least four cameras produced with curved photographic plates were successfully completed. Inexplicably, these cameras appear to have had no practical success and little further research was done until others such as George Ritchey, Henri Cretien and Bernhard Schmidt reexamined the problem decades later. Several possible reasons for the demise of this novel project will be postulated.
The Early Observatory Telescopes of Carl Zeiss.
With the onset of the 20th century, Zeiss, Jena, began fabrication of large telescopes for astronomical observatories. Instruments up to a meter in aperture were installed, mostly in European observatories, where many did not survive the 20th century. These highly engineered and meticulously fabricated instruments are now quite obscure. Zeiss engineer Franz Meyer was responsible for very innovative designs that are a hallmark of this era. The development, installation, and astronomical function of these telescopes will be described and depicted.
Trudy E. Bell.
Roger Hayward and the Invention of the ‘Two-Mirror Schmidt’.
Roger Hayward (1899–1979), now virtually unknown, was a multitalented architect, scientific illustrator, and optical inventor. Remembered primarily for illustrating Scientific American magazine’s “Amateur Scientist” column between 1949 and 1974, he also illustrated more than a dozen textbooks in optics, physics, geology, oceanography, and chemistry, several of which became classics in their fields. He designed façades with astronomical themes for major buildings in Los Angeles, California, and sculpted mammoth, realistic models of the moon for Griffith Observatory, Adler Planetarium, and Disneyland. Throughout his life, he recreationally painted watercolors and oils that at least one critic likened to the work of John Singer Sargent.
Hayward is least known as an optical designer, yet he made significant contributions to the DU spectrophotometer that established the multimillion-dollar company Beckman Instruments. During the pre-radar days of World War II at Mount Wilson Observatory, Hayward invented a classified Cassegrain version of the Schmidt telescope especially adapted for nighttime infrared aerial photography, plus extraordinarily simple machines that allowed inexperienced soldiers to grind, polish, and test accurate aspheric Schmidt correcting plates at speeds compatible with mass production—and later received U.S. patents for them all.
This paper, drawn in part from unpublished letters between Hayward and Albert G. Ingalls, will feature little-known images of Hayward’s work.
Paul L. Hermonat.
Thomas Slater of London, obscure, but noteworthy telescope maker of 1840-50s London.
There are few pieces of evidence marking the life of Thomas Slater, an obscure but noteworthy telescope maker of 1840-50s London. However, what is known is that he produced very large telescopes for that time period. Most noteworthy of these was the 24 inch great Craig refractor of 1852, the largest refractor in the world at that time, for which Slater made the lens. Slater, being the only actual telescope maker involved in this project, was likely also involved in the production of the rest of the optical tube as well. The Craig refractor is poorly known and poorly cited due to its very short operational life of about two-six years and its weak use by serious or professional astronomers. This was likely due to the death of Craig's wife in 1854. Regarding Slater, Google searches and email inquiries to various museums within the UK failed to reveal any significant information on Thomas Slater. The most information on him is present on the website