October 31, 2010 #102 - Search for a Lunar Satellite During the Eclipses of 1888 & 95

 I was reading the 1895 "Astrophysical Journal - Vol. II" and came across an article written by E.E. Barnard. The title was "On a Photographic Search for a Satellite of the Moon".  That is an intriguing thought, a satellite of a satellite. I have read that the earth has a few quasi-moons, 3753 Cruithne, 1998 UP1 and 2000 PH5, and we know that many Kuyper Belt objects and even asteroids have moons, but it had not occurred to me that Luna might have one.

In the present time frame the moons domain  has been minutely surveyed by optical, radar, and spacecraft, both manned and unmanned. Data, probably amounting to many hundreds of terabytes and being collected at a prodigious rate by multiple nations in on going programs, has failed to find a satellite of Luna. But, in the late 1800's scientists were theorizing and working to prove or disprove the hypothesis.

I have included three pertinent articles. The first is from the 1892, "American Illustrated - Vol. IX ". The second is E.E. Barnard's article and the third is a part of an article by F.R. Moulton, from a June 1899 "Popular Astronomy - Vol. VII". This is a calculation on the distance that a Lunar Satellite could survive in orbit based on the gravitational influences of other bodies.
 (Click on article to read)

Clear Sky - Rich


October 30, 2010 #101 - A Procession of Meteors on February 9, 1913

While reading through the 1922 "Popular Astronomy Vol. XXX"  I was intrigued by this article, written by William H. Pickering. This is the first time I've read about a train of meteors. I have plotted the path on a map to help me visualize the path. All I can say is this had to be quite spectacular.

(Click to enlarge for reading)

There was at least a second follow up article by Pickering but I have not been able to find it. Vol. XXX is the last Popular Astronomy that was in the archives.

Clear Sky - Rich


October 29, 2010 #100 - Alvin Clark & Sons Shop - Part 5

I had only intended to Blog four posts on the Alvin Clark & Sons story, but a couple of nights ago, while I was panning for astronomical gold on Google Books, I found a couple of nuggets in the most unexpected places. In an 1874 publication titled "The Pennsylvania School Journal" Vol. XXII and in an 1875 Weekly publication titled "The Friend - A Religious and Literary Journal". These articles chronicle visits to the Clark optical shop. They describe the shop and steps that the Clark's went through in the manufacture of their crown and flint glass lenses from start to completion.  Based on my earlier searches, I had almost zero hope of ever reading this story. Persistence can pay off in using search engines. I hope you will enjoy these articles. Once again Google Books, thank you, for these gold nuggets.

(Click to enlarge for  reading)
("The Pennsylvania School Journal" Vol. XXII" - 1874)

("The Friend - A Religious and Literary Journal" - 1875)

You may have noticed with this post I have reached one hundred entries. When I started Blogging back in July 2008, I did not think that it would be this much fun. I would recommend this type of writing as a way to challenge your mind, it dredged up old memories, taught me a lot by getting me to research my hobby of astronomy, and I have met some very nice people along the way.  What ever your hobby there are lots of people with the same interests, give it a try.

Clear Sky - Rich


October 28, 2010 #099 - Producing Lens Blanks in the 1800's

During my reading of historical journals about lens manufacture, I found information recorded on how lenses were ground and polished but very little on how the glass was manufactured to produce the raw blanks. I found an article in the 1887, "Publications of the Lick Observatory Vol. I", giving a good explanation on the blank making procedures of the period as it related to the construction of the Lick Observatory telescope. Below is an interesting explanation of the process, very time and labor intensive, but it worked.

* * * * * * * * * *

During the summer of 1874, Mr. D. O. Mills visited Washington and New York and had frequent consultations with astronomers and others, specially with Professors Newcomb and Holden in Washington, and with Dr. Henry Draper in New York.

It was decided that Professor Newcomb should go to Europe to investigate the matter of procuring the glass necessary for a large reflector or a large refractor...

Professor Newcomb's report (dated March 4, 1875) is as follows:


"I have the honor to report to the Lick Trustees, that in accordance with the request conveyed in your letter of December 3 to Mr. D. O. Mills, I have made a journey to Europe for the purpose of collecting such information as might enable the Trustees to decide upon the course to be adopted in order to secure for the State of California a telescope ' larger and more powerful than any yet made.' For this purpose I communicated with such of the leading men of science of England, France, and Germany as were most likely to give me either suggestions or information, having especially in view to learn (1) what is likely to be the limit of available size of a refractor, and (2) what optical firms could prudently be entrusted with the construction of such an instrument as that required by the Trustees. Beginning with the latter question, the result of my inquiries was, as might have been expected, that the majority of the opticians did not come within the range of the requirement. Not deeming it necessary to specify each firm by name, I may say in a general way that most of them, while of high character as men of business, had never successfully undertaken the production of a telescope of any but the smallest size, and there was no good reason to believe that an attempt on their part to make one of the size required would end in anything but failure.

Special details are given by Professor Newcomb of his negotiations with four several firms, viz.: G. & S. Merz, of Munich; Thomas Cooke's Sons, of York; Eichens & Martin, of Paris, and Howard Grubb, of Dublin; and copies of a set of provisional specifications drawn up by Professor Newcomb, and by him transmitted to these gentlemen, together with their replies and estimates, are appended to his report. As circumstances brought these negotiations to an end, it is not necessary to give this matter here. Professor Newcomb's report on the method of glass founding adopted by the two most celebrated makers has a permanent value, and is accordingly given below.

The Glass Discs.

"There are but two parties to choose from: Messrs. Chance Bros. & Co., of Birmingham, and Ch. Feil, of Paris. I regret to say that I could collect no certain evidence that either of these parties can really be relied on to furnish discs of much more than 30 inches in diameter within any reasonable length of time, and the claims of the two are so nearly balanced that I must request the Trustees to delay deciding between them until I have investigated the specimens of glass which each has furnished, in order to learn which is the best adapted to a great objective.

"The state of the case will be better understood by explaining the process of making such discs, as I learned it from the parties themselves and from others. The materials are mixed and melted in a clay pot holding from 500 pounds to a ton, and are constantly stirred with an iron rod until the proper combination is obtained. The heat is then slowly diminished until the glass becomes too stiff to be stirred longer, when the mass, pot and all, is placed in the annealing furnace. Here it must remain undisturbed for a period of a month or more, when it is taken out; the pot and the outside parts of the glass are broken away to find whether a lump suitable for the required disc can be found in the interior.

"If the interior were perfectly solid and homogeneous, there would be no further difficulty; the lumps would be softened by heat, pressed into a flat disc, and re-annealed, when the work would be complete. But in practice the interior is always found to be crossed in every direction by veins of unequal density, which will injure the performance of the glass; and the great mechanical difficulty in the production of the disc is to cut these veins out and still leave a mass which can be pressed into a disc without any folding of the original surface. Two parts or surfaces of the glass can never be joined or welded closely enough to serve the purpose; every change of shape in pressing the glass must therefore be made in the interior mass, as it were, without breaking the surface.

"The Messrs. Chance found it necessary to try a large number of pots of glass before they succeeded in producing one from which a disc of 26 inches clear aperture could be made. The time required for each trial depends on the stage of the process at which the failure is discovered. If on first breaking the pot, the interior mass is found too full of veins, only one or two months will have been occupied. But it may happen that after the disc has all been put into shape, annealed, and ground, the final trial may show a failure, and then several months will have been occupied in the trial. Practically the Messrs. Chance were four years in producing two pairs of 26-inch discs for Messrs. Alvan Clark & Sons.

"I could find only two points in which Feil's process differed from that of the Messrs. Chance:

"(1) His pots are much larger, about twice the size of Chance's, which, it seems to me, must be an advantage.

"(2) His system of cutting out the veins is more slow, careful, and elaborate.

"He reheats the glass a number of times and moulds it into shape gradually, cutting out all the veins he can reach after (each) cooling. As the glass must be re-annealed after every heating, each trial takes a much longer time than in the case of Chance, but final success is far more probable.

* * * * * * * * * *

"In the matter of finding a combination of glasses which shall be perfectly achromatic, I regret to say that my conferences with the highest authorities in Europe resulted in nothing satisfactory. Nothing can be done but to select from the specimens of glass furnished by the competing bidders that combination which gives the best results. According to Professor Stokes no improvement can now be made on the usual combination of hard crown and dense flint glass. Should this be so, I do not think any advantage will be gained by attempting more than 34 inches clear aperture."

Clear Sky - Rich


October 27, 2010 #098 - Alvin G. Clarks Double Star Discoveries - Part 4

In the past few posts are mentioned the discoveries that the Clarks made while star testing new optics. As an occasional double star observer, I researched information on these discoveries. For those observers of double stars, here is a little observational data that I found in the "American Journal of Science and Arts"  Vol. XXV - Second Series - 1858 and Vol. XVII - Third Series - 1879. The first is written by the Rev. W. R. Dawes and the second S.W. Burnham, both well known astronomers.

(By Rev. W. R. Dawes - 1858)

(By S.W. Burnham - 1879)

Clear Sky - Rich


October 26, 2010 #097 - A Visit to Alvin Clark & Sons - Part 3

I have gone through the literature looking for pictures of Alvin Clark & Sons' work shops. There are very few photos in the old archives just a few of the finished products. Visitors to the shop were frequent but there is little that anyone has written or spoken of that point to innovations or new methods of manufacturing optics. In fact it was written that conditions were quite primitive. The high quality of production optical products was due to rigorous testing, and scrupulous attention to the surface figure of the glass. All surfaces were worked by hand until absolutely to the highest tolerance. This took a lot more man hours but it was what the Clarks demanded. They did not even record journals of the work progress. Each lens got thorough attention until it was finished.
Stephen Tilford of Cincinnati, OH, on his Blog, has the only picture I've seen, that may be taken in the Alvin Clark & Sons shop.

A picture of the Yerkes lens as it was ready to be installed. This was one month before Alvin G. Clark died.
 (Click to enlarge)

 The following is an account of a visit to Alvin Clark & Sons by W.W. Payne Written in "Popular Astronomy" Vol. XV - No. 7 (August and September 1907)

Clear Sky - Rich


October 25, 2010 #096 - Alvin Clark & Sons - Part 2

In this post I will add a little more history gleaned from several 1800's vintage journals, magazines, science compendiums, and astronomy books.

Alvin Clark was born on March 8, 1804 and married Maria Pease on March 25, 1824. His first son, George Bassett, was born February 14, 1827, and the second son, Alvin Gram, on July 10, 1832. In 1844, George became interested in grinding and polishing reflectors for telescope mirrors and his father took up the work and aided his son in experimenting with this type of telescope. Taking his fathers advice they abandoned the reflector and began work on refracting lenses. Father and son continued development of optical manufacturing skills over several years and produced the first production achromatic lenses made in the United States.

The Clarks established their company in 1846 and in 1852 the younger brother Alvin Gram, trained as a machinist at the public school of Cambridgport, joined his father and brother in lens production. Among their first objective lenses was a 4.75 inch which Mr. Clark used to discover two new double stars in 1852. In 1853, with a new lens of 7.5 inch aperture he discovered 95 Ceti and reported his discoveries to the Rev. W. R. Dawes, the famous double-star observer of England, who purchased from him this lens and later four others. One of these included an 8 inch objective, which Sir. William Huggins used to make the first visual observations of stellar and nebular spectra. This added to the reputation of quality that Clark Lenses provided the observer.

In 1859 he was a guest of Rev. Dawes in England where he visited the Greenwich Observatory and attended a meeting of the Royal Astronomical Society. It was there that he met Sir John Herschel and Lord Rosse. He sold one equatorial mounting and two objective lenses,one 8 and the other 8.25 inches. The results from the use of these was published by Rev. Dawes in the monthly report of the Royal Astronomical Society. This gave the American Manufacturer a wider international reputation. Rev. Dawes paper is provided below.

From Google Books, "Memoirs of the Royal Astronomical Society, Volume 29, 1861"
(Click on document to read)

Dr. F.A.P. Bernard ordered for the University of Mississippi an 18.5 inch telescope larger than any refractors ever before in service. The delivery was prevented by the civil war and the instrument was sold in Chicago and was afterwards in the charge of S.W. Burnham. This is the lens that the Clarks were testing when Sirus B was discovered in 1862.

The Clarks produced lenses of the highest quality for many years. The elder Clark died on August 19, 1887. He was still active in the business at the time of his death. George Bassett died on January 2, 1892, and Alvin Gram died on June 9, 1897.

Alvin Gram, was also a successful observer of astronomical phenomena and discovered 14 double stars, among them the companion of Sirus. He traveled world wide observing eclipses of the sun, and the 1869 transit of Venus. He completed a 30 inch objective lens for the government of Russia, a 36 for the Lick Observatory, 26 for the Washington Naval Observatory, 26 for Leander J. McCormick of Chicago for the University of Virginia. In May of 1897 he delivered the 41.5 to the Yerkes Observatory, Lake Geneva, Wisconsin, the lens for the most powerful refracting telescope in America. Due to the extreme size of the lens blanks, it was an arduous process to secure glass of the quality required. This objective lens cost three years of labor with two assistants. The last survivor of the family of famous lens makers was in failing health as he supervised the installation and died just a month after this delivery.

The company's trained and dedicated work force, under the guidance of a 27 year associate of the Clarks, Optician - Carl Lundun, continued to manufacture unsurpassed optics, under the Alvin Clark & Sons name. The company was purchased in 1933 bringing an end to a great chapter of astronomical history.

Clear Sky - Rich


October 24, 2010 #095 - Alvin Clark & Sons Objective Lenses - Part 1

As I have been going through old Astronomical Journals this year there is one phrase that keeps occurring. Alvin Clark & Sons, produced this lens. If an observatory either professional, academic, or private needed the best quality optics they went to Alvin Clarke & Sons. So it was time for me to search out some information on their almost mythical ability to produce objective lenses.

The following history of Alvin Clark is taken from William Henry Chaffee's "The Chaffee Genealogy" 1909.

Alvan Clark, born in Ashfield, Mass., March 8, 1804, died in Cambridge, Mass., August 19, 1887. He was the famous maker of telescopes, his factory being in Cambridgeport, Mass.

" He was attacked on the Wednesday preceding his death by a stomach trouble which his advanced age rendered him unable to throw off. Up to his last illness, Mr. Clark had followed the course of his business closely, and even after he turned seventy seemed to lose little or none of his extraordinary skill of eye and hand or patience.

"Alvan Clark was born on a farm at Ashfield, Mass. He received an ordinary education, but at an early age showed a great taste for drawing and engraving. He removed to Lowell in 1826 and obtained a situation as a calico engraver in a mill. Nine years afterward he became a portrait painter, and settled in Boston. About 1843 his son Alvan G. Clark became interested in the study of optics, and the father also began to study mechanics and astronomy. They experimented together a good deal and finally succeeded in making a reflecting telescope. Mr. Clark and his son spent nearly ten years in the study of optics and the art of telescope making, and in the making of small optical instruments, before their claims in this general department of astronomical science were recognized. The Rev. W. R. Dawes, of England, celebrated for his measurement of double stars, hearing that Mr. Clark was constructing instruments of superior purity and power ordered a glass for his own use, which was duly sent him in the fall of 1853. This was the starting point in Mr. Clark's career as a maker of telescopes, for the performance of this glass so greatly excited the admiration of English astronomers, that Mr. Clark found himself suddenly famous and rapidly received orders for telescopes both at home and from abroad. Through his efforts he has given to the world the largest and most powerful astronomical instruments ever made, the results being the discovery of celestial bodies heretofore unknown. From New York to St. Petersburg, and in every civilized country of the world, the name of Alvan Clark is a familiar one among scientists.

"The famous instrument in the Washington Observatory was made by him and required four years of labor. That presented to the Washington and Lee College, of Virginia, by Mr. McCormick of Chicago, costing $40,000, came also from the careful hands of Clark & Sons. The great telescope in California bequeathed by Mr. Lick, was made in the workshop of the Clarks, and also the famous telescope made a few years ago for the Pulkowa Observatory in Russia. He is also the inventor of a double eye-piece, an ingenious and valuable method of measuring small celestial arcs.

"On the night of January 31, 1862, he and his son, Alvan G., while making some observations with a newly finished telescope, discovered the companion of Sirius, for which the French Academy of Sciences bestowed on him the Lalande Medal." [New York Tribune.]

"Mr. Alvan Clark's personal qualities so strongly influenced his achievements that they form an interesting subject of study. Most remarkable was his aversion to advertising himself or his telescopes in any way whatever. He never sought an order. He could never be induced to place specimens of his handicraft on exhibition; even the Centennial at Philadelphia had nothing to show from his hands. Astronomers the world over applied in vain for a price-list of the productions of Alvan Clark & Sons. The firm would not print anything of the kind. Nowhere was anything arranged for display. Visitors to his workshop, whatever their rank, position or objects, were received with the same unstudied courtesy, and found everybody, from the head of the firm down, in his working garb. No pretensions to a secret art were ever made. When, in travelling abroad, members of the firm found their foreign colleagues afraid to show how they worked, the only impression conveyed was that human nature had its weaknesses. Never before was an art or manufacture built up on so admirable a moral basis." [New York Nation.]

The only Alvin Clark & Sons advertisement I have found was in an issue of Popular Astronomy dated after the last of the Clarks died..

More to the story on the next post.

Clear Sky - Rich


October 23, 2010 #094 - Thoughts on Astronomical History

In my fun research into Astronomical History I am struck by how little people have changed over the past 250 years. On the earth we have been through much human struggling, slavery, suffrage, women trying to raise their standing in a male dominated society, political strife, competing economic systems, degradation of the environment, the fight for land and resources, the list goes on and on!

One of the surprises that has hit me as I delve into the past is that the world of Astronomy was not above it all. I, in my naive way thought that the field was on a higher plain. How could the study of the Cosmos, one of the purest sciences, be corrupted. I forgot one important fact, astronomy is conducted by human beings.

Within my lifetime I have read about the fights to build observatories on mountain tops that were the habitat of the last remnant of a fading species of plant or animal. There were political and economic battles over the prestige of having the latest technologically advanced astronomical instruments built in a specific country. Then of course there is the battle of egos, as a scientists work is refuted by a contemporary or  the next generation of researchers.

One of the most obvious shortcomings of the astronomical community in the past was the value placed on women's contributions to the field. It is plain that many of the major accomplishments of the past were made by women working in the background, assisting husbands, working as human computers calculating data, sifting through millions of photographic plates, and contributing understanding to the field with brilliant minds, only to have it presented by others in papers and at gatherings of "Astronomers".  Many of these great women were only recognized after they passed away, in obituaries of the time printed in obscure journals.

I might refer you to POPULAR ASTRONOMY 1898 Vol. VI (Woman Astronomers 400A.D. - 1750), (Woman Astronomers 1750 - 1890), and (Woman Astronomers Contemporary) Written by Herman Davis. This is a good primer on the subject. It can be read on Google Books.

Below are a couple clippings from my historical "scrapbook" that I think illustrate how things have changed very little. 

(Click on picture to enlarge for reading.) 

I don't recall my wife ever waking me and telling me that the occultation was about to start or wasn't the eclipse of the moon supposed to be about now. But then she did wake me for work when I had spent to long at the eyepiece, probably way more important in the scheme of things.

I guess this means that employees were just as unhappy with the boss in 1913 as people are today.

Clear Sky - Rich


October 22, 2010 #093 - Unique Meteor Sightings From Collection

In this post I would like to pass along some unique historical meteor sightings that I have collected. The  drawing is from South America and I have no source or date for it. The clippings are from various old periodicals from dates in the 1800's and early 1900's. I think you will agree that some are quite spectacular. It strikes me that the fall in Lake Ontario has a location documented well enough that it might be possible for a boat towing a magnetometer to locate the fall. I'm sure a large diameter iron meteor would set off the detector.

(Click on the individual page to enlarge it for reading)

Clear Sky - Rich


October 21, 2010 #092 - The "Fiery" Meteor of 1783

One of my astronomical researches (for fun) projects has been to collect historical accounts of meteor sightings. There seems to be one account that stands out in the literature as Europe's most spectacular appearance. In the fall of 1783 a meteor entered the earths atmosphere over the North Sea traveled across the British Isle, crossed the Channel onto the Continent, and may have made it 1000 miles to Italy. As it traveled it threw off pieces and varied greatly in brightness.

(The pictures source and artist are unknown
but this is a contemporary representation of the event)

I found this account in "The Edinburgh Magazine" dated 1785 on Google Books. The article is included below. If you search you will find many references to what must have been a major event of the times and witnessed by tens of thousands of people.

(Click on the pages to enlarge for reading and remember,
at that time printers exchanged "f" for "S")

Clear Sky - Rich


October 20, 2010 #091 - Visiting Martian & Lunar Lava Tubes

I went somewhere last night that I thought I would never be able to go in my wildest day-dreams. Having sat glued at my telescope eyepiece for hours, watching the moon passing below as the earth turned, it gave me the illusion of gliding in close orbit, but that was as if the eye was still miles above the surface.

In no way would I ever to be able to stroll freely where my feet would take me. Even the men who have actually been to the moon remained within relative close proximity to their lunar module, and who knows if we will ever walk on mars!

Thanks to NASA we now have two of the most remarkable data bases that could be imagined. LROC, the Lunar Reconnaissance Orbiter Camera, and HIRISE, High Resolution Imaging Science Experiment. With their data your computer allows you to take a vantage point close enough to the surface for the eye to resolve the surface features a few feet across and in some cases inches.

I was "virtually" close enough to follow the trails of rocks rolling down hills on other worlds, cross lunar and martian bridges, see the tracks of Lunakhods, peer down where the roof collapsed into lava tubes, admitting the suns illumination where once glowing lava flowed. In my younger days I was able to walk through actual lava tubes in Idaho, so it took very little imagination for my minds eye to visualize where I could not yet travel, below the surface of another world. BUT, I stood on the edge of a pit on Mars last night and yearned to explore the unknown world below.

Below is what I saw standing on Mars & Luna.
(Click to enlarge)

Top image from HIRISE data and Bottom from LROC data.

Clear Sky - Rich