Counting Stars

Counting Stars Blog BannerWelcome to the musings and maunderings of the staff of Dudley Observatory at the Museum of Science and Innovation.

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Goulds all the way back

There’s one advantage to inheriting a library; you don’t just get the books, you also get the bookmarks.  This bit of paper was found in one of the books used by Benjamin Gould.  On one side are some calculations.  On this side is a rough family tree.

Like any good Boston pure-blood, Gould was very interested in his own genealogy.  I know we’ve got some fans who can trace their lineage back to Gould’s family, so I thought this might be useful.

In the third column, the John Gould that is married to Sarah Parker would probably be Lieutenant John Gould (1635-1710), who served during King Phillip’s War.  Since he had eight children, you can see that this listing is very partial.

Benjamin A. Gould Family Tree (Gould Papers, B6,F6)

Benjamin A. Gould Family Tree (Gould Papers, B6,F6)

I’m afraid that all future generations will find in my books are the backs of Netflix envelopes and old receipts.  I feel like I’m failing history.


grand theodoliteIn regards to the last post, here’s Verplanck Colvin himself, taking notes on the right.  The instrument he’s using is called a theodolite, which is essentially a small rotating telescope for measuring horizontal and vertical angles.  Well, I guess in this case it’s not really a small telescope at all.  That looks like a brass telescope, maybe 4″ or so.

Colvin called this his “grand theodolite,” and last I checked, no one was sure where it had ended up.  Such a big and impressive big of technology porbably wasn’t scrapped (although, given that he and his crew had to hump this thing up and down a mountain, they probably wanted to).  If anybody has any idea, I’d love to know what happened to it.













barometerHere’s a less portable piece of technology.  This is George Washington Hough’s “automatic registering and printing barometer.”  It was Hough’s pride and joy.  He the bulk of the second Dudley annals describing it and showing tables of its results.

The object labeled B is a cylinder of mercury attached to a support frame that is bolted to a brick wall in the observatory.  A float is suspended in the mercury which rises and falls reacting to changes in the air pressure.  Changes in the position of the float trigger electromagnets, which release gears in the mechanism and cause the pen arm, S, to change position to match the float.  A drum wrapped in paper, O, rotates against the pen, recording a steady line that peaks and dips with the pen arm.

The weights at the bottom power the gears and the drum.  A battery powers the electromagnets.  By using batteries just to lock and unlock the gears, the use of electricity could be kept to a minimum.  Important in an are where recharging batteries required refreshing the chemicals.

Obviously it’s more complicated than I’m making it sound, but Hough was able to make it work.  It’s probably worth mentioning that when Hough was laid off in 1873, he went into private business selling his own inventions and was apparently successful.

How to Measure a Mountain Without Leaving Your Observatory

Nineteenth century observatories were more than just places to look at the stars.  They were packed with scientific instruments that were useful for all sorts of purposes: highly accurate clocks, barometers, thermometers, transits and other surveying equipment, and so on.  Many observatories were staffed by people eager to reach out to the public, either as part of their mission or to justify their funding.  Observatories could become little temples of science for their community.

As a rare privately funded observatory unattached to a university, Dudley had (and has) a strong need to be useful to the community which created it.  I’ve mentioned Benjamin Gould’s plan to provide accurate time for New York.  Since time is a measure of the earth’s rotation, the observatory could help mapmakers determine longitude. Dudley also offered public viewings to all, right through the Civil War.

Here’s one interesting example of Dudley making its scientific resources available.  In 1870, the naturalist and engineer Verplanck Colvin was working on a geological survey of the Adirondack region.  As part of this project he completed the first recorded ascent of Seward Mountain.  To complete his survey, he needed to know roughly how tall the mountain was.

One way to work out the height of a mountain was to take barometric readings at the top.  Since air pressure is lower the higher you climb, you can compare those numbers with readings taken from close to sea level.  By working out the difference, you can figure out the difference in elevation.

For the best accuracy, the readings should be from the same region and at the same time.  But synchronizing time can be a little tricky when you’re on the side of a mountain.  Fortunately for Colvin, in 1870 the head of the Dudley Observatory was George Washington Hough.

Hough was not only an astronomer, but also an inventor.  And his pride and joy was a self-reading and printing barometer, which could keep track of changes in the barometric pressure and keep record of when they happened.  So when Colvin came down from the mountain, he could send his notes to Hough, who would compare Colvin’s readings with his own records from the appropriate time.

Colvin took the results and presented a report at the Albany Institute.  Fortunately for us, he included the text of the letter he received from Hough:

Letter from George Washington Hough to Verplanck Colvin

Letter from George Washington Hough to Verplanck Colvin

The result was significantly lower than previous estimates, but not far off of the current measurements.  It’s a small thing, but it helped establish Colvin as a serious surveyor and helped him gain funding for his continued work in the Adirondacks.  And that is important for New York, because Colvin became the father of the Adirondack Park.

Immediately after this presenting this letter, Colvin began to describe the damage caused by lumbering that he had seen from Seward Mountain.  He proposed that the Adirondacks become a state park to protect the forest.  He cleverly tied the preservation of the forest land, which shielded lakes and snow packs, with the need for water in the Erie Canal.  It became a major theme of his work.  When he was later appointed the superintendent of the New York state land survey, he oversaw the creation of the Adirondack Forest Preserve in 1885.

Making New Mirrors

Proof of Concept for Silica Mirror (Thomson Papers, B#6, F001)

Proof of Concept for Silica Mirror, 36″ (Thomson Papers, B#6, F001)

This doesn’t look like much, but it was the start of something that was going to revolutionize the field of astronomy.  This is a disk of silicon dioxide, also known as silica.  Since it is made from very clean quartz sand, it is also known as “fused quartz”.  You can think of silica as being very pure glass without any additives.

Those additives serve a purpose.  They lower the melting temperature of the silica.  Without those, silica can require a furnace at 3,000 degrees Fahrenheit to work with.  But removing those additives means that you have a type of glass that is very resistant to changes in temperature.

One of the first people to see the advantages in this was Elihu Thomson, a scientist, engineer and businessman who founded the Thomson-Houston Electric Company.  This company later merged with Edison General Electric to create the General Electric company we’re familiar with today.

Since fused quartz is so resistant to heat, it has been used in high temperature applications like halogen lamps and furnaces.  It’s strong, so it has been used in bathyspheres and other high-pressure devices.  But Thomson was an avid amateur astronomer, and he saw a use for silica that others might have missed: telescope mirrors.

Since silica resists changing shape with heat, it could be used in unheated observatories that could get blistering hot or freezing cold without distorting the viewing.  It could also resist the heat produced by grinding and polishing, which made it easier and faster to work with that regular glass.  Mirrors could be produced faster and – more importantly – larger than ever before.

In the late 1920s, when George Hale convinced the Carnegie Institution to fund the construction of a new telescope for the Palomar Observatory, he was thinking big.  Hale had already worked on the largest telescope in the world: the 40-inch refracting telescope at Yerkes Observatory, 60-inch Hale reflecting telescope at Mount Wilson Observatory and 100-inch Hooker reflecting telescope at Mount Wilson.  For his next – and final – telescope, he would require a massive 200 inch mirror.

This was probably beyond the conventional technology of the time.  Hale needed to try something new.  He ended up turning to Elihu Thomson and his idea for a fused silica mirror.

The lump at the upper right was a proof of concept.  The next mirror would be a sixty inch disk, and no one had worked with silica on that scale before.  It required new techniques and the construction of new furnaces in Thomson’s Lynn, Massachusetts plant.

Construction of a experimental furnace for the 60-inch Palomar Mirror (Thomson Papers, B#6, F006a)

Construction of a experimental furnace for the 60-inch Palomar Mirror (Thomson Papers, B#6, F006a)

In the end, it took three years to produce two sixty-inch mirror.  The first mirror was of excellent quality, but it cracked during the cooling process.  The second mirror was marred by air bubbles.  Thomson and  General Electric had proven that large scale silica mirrors could be made, but that wasn’t enough.  Hale needed something produce quickly, and at a reliable price.

So the 200-inch mirror was not made in a Schenectady factory, but in Corning Glass works.  And instead of silica, it was made of Pyrex.  One of the first attempts at the 200-inch mirror is on display at the Corning Museum of Glass.

It’s a little frustrating, but it’s a good example of the difference between a new technology and a more mature technology.  Pyrex had been invented in the 1890s, about the same time that Thomson began experimenting with fused quartz.  But Thomson was a businessman, and a busy one.  There was no immediate need for silica mirrors, and the potential market seemed small.  General Electric had plenty of other things to do.

Corning invested more time and energy into Pyrex, and so they went into the process with more confidence.  They succeeded in six months when GE it had taken three years to not quite pull it off.


“A Deed of More Perilous and Romantic Courage has Perhaps Never Been Undertaken …”

Ormsby MacKnight Mitchel (1810-1862)

Ormsby MacKnight Mitchel (1810-1862)

Ormsby MacKnight Mitchel was a tireless scientist and engineer who deserves a share of the credit for shaping American astronomy.  He was an institution builder and a self-taught astronomer responsible for starting both the Cincinnati Observatory and our own Dudley Observatory.  He was also an  inventor, and his chronograph  allowed a single astronomer to both make observations and record the exact time the observation was made.  This made the star catalogs late 19th century possible.

But for all that, Mitchel is likely to be best remembered for something that has nothing to do with astronomy.

Mitchel helped found the Dudley Observatory and became the director, but he never set foot in the building.  That’s because the Civil War started before he made it to Albany.  Mitchel entered into the Federal Army with a reserve rank of brigadier general and organized defenses around Cincinnati, Ohio, then moved into Kentucky and Tennessee.

It was in Murfreesboro, Tennessee, in April of 1962 that Mitchel saw an opportunity.  He was not far from rebel-held Chattanooga.  He could take Chattanooga, but there was a rebel held railroad running from the city down to Atlanta, Georgia, that would bring up rebel reinforcements.  But if that railway was somehow destroyed, then Mitchel could hold Chattanooga and win a major victory.


James J. Andrews (1829-1862)

Mitchel didn’t have the troops to attack both Chattanooga and the well defended railway.  That meant it was time to get sneaky.  Mitchel worked out a plan with a civilian spy named  James J. Andrews.  The agent would lead two dozen Union soldiers in plain clothes down to Atlanta.  There they would steal a locomotive engine and flee back towards Chattanooga, destroying the railway bridges as they went.  Then they would shoot through Chattanooga and rejoin Mitchell’s army.

The plan started off without a hitch.  Andrews and his men slipped into Marietta, just north-west of Atlanta.   Meanwhile, Mitchel successfully took Huntsville, Alabama, which would be Andrews’ destination after the operation.   Two of Andrews’ men were accomplished engineers, and they slipped into an unattended train named The General, uncoupled it from the baggage cars and steamed off with their stolen engine.

Things fell apart not long thereafter.  Despite their haste, they were required to sit for twenty minutes on a side track to let another train pass.  This was enough time for the rebel troops in Atlanta to figure out what had happened and set off in pursuit with their own engine.  Andrews and his men had to abandon the plan and steam ahead as fast as possible to escape their pursuers.

What followed was a hundred mile railway chase which has become legendary in American history.  Dubbed The Great Locomotive Chase,  it captured the imagination of the American public.  The popular historian John Stevens Cabot Abbot wrote a breathless article about the raid for Harpers in 1865 from which I took my title, “Heroic Deeds of Heroic Men.”  It has been the subject of probably a dozen books, starting with Daring and Suffering by one of the participants, to the recent Stealing the General by Russell Bonds.  It was the inspiration for Buster Keaton’s 1926 movie “The General,” and in 1956 it became a Disney movie starring Fess Parker (AKA “Davey Crockett”) as James Andrews.

The Disney film got mixed reviews, likely because the ending was downbeat.  Andrews and his men ran out of fuel and had to abandon their engine.  They were rounded up and imprisoned. Eight, including Andrews, were eventually hanged.  Their mission failed, and Mitchel did not take Chattanooga.  He would die six months later of yellow fever.

The bravery and ingenuity of the men involved has not been forgotten.  When the Medal of Honor was created in 1863, one of the raiders named Jacob Parrott became the first recipient.  Unfortunately, James Andrews himself could not receive a posthumous awards since he was an espionage agent and not officially part of the military.  He is remembered on a monument at the Chattanooga National Cemetery.

Recovering the History of Women Computers

As an archivist, I’m not used to covering topical issues.  But the history of women computers in the field of science is suddenly getting a lot of attention.  The latest is the film “Hidden Figures,” which follows four African American women and their careers as mathematicians in Langley Memorial Aeronautical Laboratory’s computer pool.  It’s based on the book by Margot Lee Shetterly and it’s slated to hit theaters late this year.

I’ve already mentioned the documentary called The Computers, which focuses on the women who became the first programmers of ENIAC.  More general is the PBS documentary Top Secret Rosies about the women who did ballistics research during WWII:

All this comes as new research shows that women were basically marketed out of the field of computer science during the early days of home computing.  Starting in the mid eighties, the percentage of women in the field of computer science began to drop out of proportion with their presence in other STEM fields.   The dominate theory right now is that home PC’s were specifically marketed to the public as a boy’s toy, creating the perception that all computers and coding were part of the masculine realm for some reason.  This created the stereotype of the male computer geek, and also edged young women out of the discipline.  The discussion is well covered by the Planet Money podcast:

HENN: Now, it’s hard to say if this is straight-up sexism or computer makers just had data that boys were a more receptive audience, but whatever the reason, this fed on itself. In the mid-’80s, you could turn on the TV and see women doctors on “St. Elsewhere.” Claire Huxtable was a lawyer on “The Cosby Show” – cops? – “Cagney & Lacey.” But pretty much anytime a computer was turned on, it was a male nerd running it. Think “WarGames,” “Revenge Of The Nerds,” “Weird Science.”

[…]HENN: By the mid-’90s computer science departments had been transformed. Carnegie Mellon, which had one of the best programs in the country, was 93 percent men. The number of women entering the field had slowed to a trickle …

The focus now is on changing this perception.  As I pointed out last time, the history of American astronomy is intertwined with the history of computer science and women mathematicians.  Astronomy may be the path forward once again.

What Happened to the Women Computers?


I’ve spoken about the Dudley Observatory’s corps of women computers several times now.  Every time, someone has come up to me afterwards to mention that, back in their day, there still were departments of women working low level mathematical jobs.  Without giving away anyone’s age, I can say this runs up until the seventies.

This makes sense.  Although the job would change, the fundamental forces that creating the teams of women computers would stay the same: the job was tedious, time consuming and low status, making it suitable women’s work in a time of nearly unquestioned gender roles.  And women could be hired in greater numbers because they could be paid less, allowing large teams to be created.

And there’s no reason that it should be confined to the field of astronomy.  The factory model of doing mathematical equations seems to have been born in astronomy, but it was too useful to stay there.  

One field where number crunchers were in great demand was ballistics.  During WWI, the militaries of the world realized that the equations for cannon trajectories did not work for modern anti-aircraft guns and bombs dropped from zeppelins.  And so a proving ground for modern weapons was set up in Aberdeen, Maryland, and an office of experimental ballistics was set up in Washington under Major Forest Ray Moulton.

Army ballistics computers in Washington D.C. Taken from Grier's "When Computers Were Human"

Army ballistics computers in Washington D.C. Taken from Grier’s “When Computers Were Human”

In civilian life, Moulton had been a professor of astronomy at the University of Chicago.  This worked well, because the equations for the flight of artillery shells used some of the same calculus as plotting the path of a comet.  And when Moulton went looking for computers, he used the same process used in astronomy and began hiring both men and women. His chief computer was Elizabeth Webb Wilson, a graduate of George Washington University with a degree in mathematics.  

About the time that Dudley was completing its massive star catalog, Virginia Tucker was being hired by Langley Memorial Aeronautical Laboratory to work in a new computer pool.  From 1935 until 1946, Tucker would help calculate drag from wind tunnel tests (another factor in ballistics) in what would eventually become America’s space program.  By the end of WWII, Tucker was overseeing some 400 women computers working throughout the laboratory.

The idea of women computers persisted, even as the equipment went from being pencil-and-paper to adding machines to punch cards.  Eventually the title of “computer” was transferred to the device and the human operator became a programmer.  But the same forces still applied, and so the first programmers were women.

Betty Jennings and Frances Bilas setting up ENIAC

Betty Jennings and Frances Bilas setting up ENIAC

For example, during WWII the Aberdeen Proving Grounds went to work again, this time with 80 women employed at the University of Pennsylvania to calculate ballistic trajectories. In 1945, six of these women were tapped to program a new device known as the Electronic Numerical Integrator And Computer or ENIAC.  ENIAC is regarded as the world’s first electronic digital computer, making these six women the first programmers in the modern sense.

So there is a direct line between the crews of female computers in observatories like Dudley and the early days of programming.  This story of women’s key role in the trenches of mathematics and programming is a story that is just now being told.  I would recommend David Alan Grier’s book When Computers Were Human for an overview, and the new documentary “The Computers: The Remarkable Story of the ENIAC Programmers” for that chapter of the story.  Of course, that’s not the final chapter by any means, but the rest will have to wait for another post.

Where Was Dudley? Part 2

In 1892, Dudley Observatory director Benjamin Boss took stock of the observatory’s position in the field of astronomy and found it wanting.  Dudley was had fallen behind the times, with no equipment to do spectroscope work and no telescope capable of doing photo-astronomy.

Worse, the position of the Dudley made fixing these problems difficult.  The first Dudley observatory was too close to four tracks of the New York Central railway, and the vibrations would throw off the careful calibration of any instrument the observatory used.

So Boss negotiated with the city for a land swap.  He gave up the site of the first observatory, with its hordes of goats, and traded it in for a site to on the grounds of the Albany Alms House.  The Alms House provided minimal housing and work for the indigent in Albany, and the rest of the grounds provided the farm land to sustain it, plus a cemetery.


(Thanks to Hoxsie for the image.)

Above you can see the Dudley Observatory, placed within the distinctive triangle of what are now South Lake, Myrtle and New Scotland Avenues.  The Alms House Hospital has been replaced by the Albany Medical College, and the Alms House itself has been replaced by the Albany College of Pharmacy and Albany Law School.

The second building is Dudley’s most famous, and it was one of the most iconic buildings in Albany at the time.  It showed up in postcards and maps of the era.



The second building is Dudley’s most famous, and it was one of the most iconic buildings in Albany at the time.  It showed up in postcards and maps of the era.  It was an imposing Romanesque structure of red brick, two stories tall with an observatory tower at the western end.  To the east was the residence of the director and temporary housing for visiting astronomers.  In the center were the rooms for the computers, the library and the rooms for the resident astronomers.

This time the patroness for the Observatory was Catherine Wolf Bruce, daughter of the industrialist George Bruce, who helped fund many great observatories around this time.  In the end she would donated $35,000 to the move and the construction of the new building.

Dudley burnedThe second Dudley Observatory burned down in May of 1970, as you can see in this photo from the Times Union Collection.  It was already empty.  Dudley had soldthe building to Albany Medical Center and moved out in the mid-1960s.  All the equipment, including the Pruyn Telescope, was packed away in a warehouse, so it was undamaged.  The gutted building was torn down and replaced by the Capital District Psychiatric Center.

The third home of Dudley Observatory was a simple office building at 100 Fuller Road in Albany, where scientists and engineers worked under Curtis Hemenway on a number of projects for NASA, most notably on micrometeorite research.  And the current home is, of course, here at miSci.  Hopefully we’ll be staying awhile.

The Great Patroness: Blandia Dudley

Blandina Bleeker Dudley bas relief by Erastus Dow Palmer

Blandina Bleeker Dudley bas relief by Erastus Dow Palmer

Writing about Blandina Dudley can be tricky.  I can wish it were different, but almost all of our sources focus on her relationship with the men around her.  Basically, any discussion of Mrs. Dudley fails the Bechdel test.

Mrs. Dudley was born Blandina Bleecker, part of the prosperous Dutch Bleecker family.  Her great-grandfather, Jan Jansen Bleecker (1641-1732), emigrated to American in 1658.  He started out as a blacksmith, but quickly became financially successful as a merchant, surveyor and land speculator.  Most famously he owned part of the Saratoga patent that included Bemis Heights.  He was politically successful as well, serving in various roles in Albany politics, including Mayor in 1700.

Jan Jansen’s grandson, Rutger Bleecker (1745-1831), continued the tradition of land speculation and surveying.  Somehow after the Revolution he ended up with a fair amount of property seized from Tories and became very wealthy from the sale.  Rutger’s wife, Catharina Elmendorf, gave birth to Blandina in 1783.

And now we run into problems.  We know nothing about Blandina’s life until she marries Charles Dudley, and then nothing until after his death.  Her connection to the Observatory begins in 1851, when she supported the original capital drive to build an observatory by donating $10,000, around $300,000 in today’s money.  When she did so, she cited her late husband’s interest in astronomy and mentioned a honeymoon stop at the Greenwich Observatory.

Things get complicated after that.  Once again, Blandina is surrounded by men who take up most of the spotlight.  The banker Thomas Olcott and one of her nephews convinced her to up the donation to $13,000.  That allowed Olcott to claim credit for this and later donations, as if Blandina’s actions were not really her own.

One way or another, Blandina remained one of the most reliable supporters of the observatory.  When the Lazzaroni struck their deal with James Armby to support the observatory in return for the purchase of some specialized equipment, it was Blandina who agreed to foot the bill for the instruments.  (The most expensive item, the heliometer, never got made, so it’s not clear she ended up paying.)

On the day of the inauguration, Blandina donated a further $50,000.  When all was tallied up, Blandina donated around $105,000, around $3 million in today’s money.   It was a remarkable donation during the years leading up to the civil war.

American observatories have a knack for selling immortality.  Real estate magnate James Lick would be forgotten, except perhaps as the man who introduced America to Ghirardelli chocolate, if he hadn’t paid for Lick Observatory.  Charles Tyson Yerkes would be grimly remembered as one of the most corrupt men in America had he not funded the Yerkes Observatory.

So it goes with Blandina Dudley.  Oddly, despite the fact that she named the Observatory after her late husband, we remember her and forget him.  Unfortunately, we remember that she donated the money, and that’s about it.  As always, I’m convinced there’s a trove of letters out there just waiting to shed some light on the rest of Blandina’s life.  If anyone has stumbled across something involving Blandina Bleecker Dudley, please drop us an email.