From the Library: Solar Cooker

Here’s another “what is it?” from the image collection:

Vertical Access Solar Furnace at Fuller Road Laboratory, ca. 1970s

If you’re like me, you associate the phrase “solar cooker” with a summer camp construction project made out of cardboard and aluminum foil, used to toast a marshmallow.  But that’s not the limit of solar ovens.  At the extreme end of the range, the Odeillo solar furnace is southern France is capable of producing temperatures of  3,500 °C.  Or course, it’s over 50 meters tall.  Still, much more modest solar furnaces are still capable of producing usefully high temperatures.

This device, called a vertical access solar furnace, could focus sunlight into the small dome seen in the center.  A small sample of material could be placed in the center dome, and it would then be subjected to a beam of extremely powerful light capable of heating the sample to high temperature.  I haven’t found a record of how hot it could go, but a slightly larger version of this device in Texas managed 3,000 °C.  These temperatures could simulate the  extreme conditions that particles could experience in space or when entering the earth’s atmosphere.

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.

Skywatch Line for Wednesday, September 14th and Thursday, September 15th 2016

This is the Dudley Observatory Skywatch Line for Wednesday, September 14th and Thursday, September 15th written by Louis Suarato.

The 95% illuminated, waxing gibbous Moon rises at 5:57 p.m. in the constellation Aquarius Wednesday. As the sky darkens, you’ll be able to locate the globular cluster, M2, about ten degrees above the Moon. Discovered in 1746 by Jean-Dominique Maraldi, M2, at 175 light-years in diameter, is one of the largest known globular clusters, and contains 150,000 stars. M2 is 37,500 light-years from Earth, and is estimated to be about 13 billion years old, making it one of the oldest globular clusters in the Milky Way Galaxy. M2 can be seen with the naked eye under optimal conditions, but better viewed through binoculars or a small telescope. Larger telescopes will resolve individual stars within this cluster.

Mars and Saturn are now separated by 13 degrees, and can be found over the south-southeastern horizon between the constellations Scorpius and Ophiuchus. If you look 20 degrees above Saturn, you’ll find globular cluster M10 in Ophiuchus. Look four degrees to the right of M10 for globular cluster M12. Both globular clusters were discovered by Charles Messier in 1764, M10 on May 29th, and M12 on May 30th. Ophiuchus is also the home of the Summer Beehive open star cluster. Look about 15 degrees above M10 for this open cluster. The Summer Beehive, or IC 4665, is a large cluster that can be viewed through binoculars.

The nearly Full Moon rises at 6:34 p.m., Thursday, a half hour before sunset. Use the Moon on this night to find Neptune. Look for Neptune 2 degrees to the right of the Moon. At an average distance of 30.1 astronomical units, Neptune is the eighth, and farthest known planet from the Sun. One astronomical unit is equal to 93 million miles. Neptune is not visible to the naked eye, so, use binoculars or a telescope to view this planet.

The Albany Area Amateur Astronomers invite you to join them for their monthly meeting this Thursday beginning at 7:30 at miSci in Schenectady. This month’s speaker is Albany Physicist Dr. Vivek Jain. Dr. Jain is part of the team that manages the ATLAS instrument, one of two general-purpose detectors at CERN, the European Organization for Nuclear Research. Dr. Jain will be discussing the link between particle physics and Cosmology. The directions to miSci can be found at

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.

Where Was Dudley?

I get this question a lot.  Actually, I usually get “Where IS Dudley?”, which requires me to explain that we don’t have an observatory at the moment, but we’re working on it.  But after that, someone has to explain where the two Dudley Observatory buildings were.

Fortunately, because the Observatory’s  latitude and longitude needed to be known to a precise degree, it’s not difficult to pinpoint where the buildings originally stood.  Both observatories were major Albany landmarks, so they’re usually not hard to find on old maps.

The first Observatory was located on land donated by Stephen Van Rensselaer IV, plus a few bits and pieces purchased in the 1850’s from the neighbors.  It’s to the north of Albany, about where Arbor Hill Elementary stands today.  Thanks to the historic map overlay put together by the Albany Bagel Company a few years ago, we can show exactly where:

Left: 1877 map  Right: 2016 Google map

Left: 1877 map
Right: 2016 Google map

The 1877 map also clearly shows the railroad line that forced Lewis Boss to abandon the original building.  When the observatory was opened, there wasn’t enough rail traffic for it to matter.  But by the 1870’s and 80’s, the steady stream of locomotives passing nearby caused enough vibration that it wrecked the calibration of the telescopes.  There was also the occasional puff of smoke that entered the observatory building.  All in all, it’s not surprising that the building burned down after it was abandoned.

The unofficial name for the rise on which the observatory sat was “Goat Hill,” because the the large number of feral goats that grazed on it.  One of the astronomers, Richard Hawley Tucker, wrote that, “There are hundreds of them in the neighborhood.”  In a letter to his mother he explained that they were, “taking advantage of the somewhat dilapidated condition of our fences and our own devotion to higher pursuits they come in crowds.  Prof [Lewis Boss] has a pistol with which he peppers them with fine shot, and usually he only needs to shout to make them scamper.”  Never let it be said that astronomers don’t know how to have fun.

More on the second observatory in another post.

The Lazzaroni

InaugurationGiven that the Inauguration of the Dudley Observatory took place right after the AAAS convention, it’s not surprising that many of the attendees were scientists.  However, some of the names of the list of attendees stand out: Alexander Dallas Bache, superintendent of the foremost scientific institution in America at the time, the US Costal Survey.  Benjamin Osgood Peirce, influential mathematician at Harvard.  Louis Agassiz, internationally famous naturalist.  Joseph Henry, pioneering electrical engineer and the first director of the Smithsonian.  Wolcott Gibbs, prominent chemist, soon to be at Harvard.

These men were some of the leading scientists in America at the time.  These names, along with other attendees like James Dwight Dana, James Hall, and of course Benjamin Gould, make up an impressive list of some of the best and brightest.  But all these names have another thing in common: they were part of a group known as the Lazzaroni.

On one hand, the Lazzaroni were just a group of like-minded colleagues in the field of science who agreed to get together during conventions to “eat an outrageously good dinner together”.  On the other hand, the Lazzaroni were a clique of influential scientists who all agreed that American science needed to become more professional along the lines of German science.

The name “Lazzaroni” sounds like a pasta, but was an Italian term for beggar, and it was probably an ironic reference to the poor state of science on early 19th century America.  As Benjamin Gould discovered when he returned from Europe, American science simply didn’t have the tools that European scientists had, nor did they have the resources to build the tools.  America needed scientific institutions if it was going to compete.

Joseph Henry, Albany Native, scientific pioneer and first director of the Smithsonian

Joseph Henry, Albany native, scientific pioneer and first director of the Smithsonian

The Lazzaroni, in between meals and drinking, agreed that building these institutions should be a priority, that the right sorts of people should be recruited to lead them.  Probably their greatest achievement was the creation of the National Academy of Sciences, founded by congress in 1863 to act as scientific advisers to the government.  They also backed a plan to create a university and an observatory in Albany, although not at the same time.  That takes a little explaining.

As I mention previously, it was James Armsby who originally suggested that an observatory be added on to plans for a world class university to be built in Albany.  While Agassiz supported the idea, the rest of the Lazzaroni were opposed to spending the money.  America had two world class refracting telescopes at that point; one in Harvard and one in Cincinnati that was inactive as Ormsby Mitchell toured the country raising money for staff.  Adding a third didn’t seem to advance American science much while taking away resources that could be better spent.

The plan for a university died when the state legislature would not fund it, but thanks to the efforts of Mtichell and Armsby the observatory found private funding from donors like Blandina Dudley.  At that point, the Lazzaroni started to come around.  They worked out a deal with the Armsby that would shape the purpose of the new observatory: if Dudley would purchase instruments for very careful measurements of stellar objects, like a heliometer and a transit circle (more on these later), then the Lazzoroni would throw their considerable weight behind the project.

In essence, the Lazzaroni wanted a specialized observatory that would complement the work that the Costal Survey was doing.  In return, Dudley got a three of the biggest names in American science on their board: Alexander Bache, Joseph Henry and Benjamin Peirce.  And one other, not quite so big name: Benjamin Gould.

It’s tempting (and fun) to make the Lazzaroni into some kind of shadowy conspiracy.  The “professionalization of science” was a profound shift in American thought, but it is maddeningly vague and hard to define exactly what happened.  The Lazzaroni give historians something tangible to point to: a group of elite white men in smoke-filled back rooms conspiring to take over American science and fill it with the “right sort” of people (See?  Fun.)

But it’s easy to make too much of them.  Here at Dudley, they failed repeatedly.  They could not get the state to support a new university, and they eventually lost their influence over the observatory.  Still, their deal with Armsby gave Dudley it’s trajectory as something more than a meeting place for local stargazers.  Dudley would become a world class observatory doing careful measurements of the heaves, but not until the Lazzaroni were kicked out of the place.

An Event of No Ordinary Interest

On August 28, 1856, at the end of a conference for the American Association for the Advancement of Science (AAAS) in Albany, the visiting scientists met with many of New York’s political elite to witness the inauguration of the Dudley Observatory.  The event probably looked something like this:


This is a painting by Thompkinss Matteson (1813-1884), a successful painter out of New York City and Sherburne, NY.  It’s a fairly large piece – 56 x 72 inches – and it was completed the year after the inauguration.  Completed for whom is the question; there doesn’t seem to be any record of the painting until it was donated to the Albany Institute of History and Art in 1917.  No one knows who commissioned it.  That’s actually important, because the inauguration brought together several competing factions in Albany politics.  Depending on which faction commissioned it, there may be some faces missing.

Many of the faces are too vague to identify.  Most of those that can be seen have been identified.  Here Dudley is indebted  to Norman Rice, former director of the AIHA, Ian Bartky and Christine Bain of the NYS Library for painstakingly matching faces to portraits and identifying the people pictured here.  Their conclusions were published in a paper titles “An Event of No Ordinary Interest: The Inauguration of Albany’s Dudley Observatory,” in 1999.

Interestingly, several of the people pictured here were probably not in attendance.  Former President Millard Fillmore is pictured on the far left, but there is no record that he was attending. Matthew Fontaine Maury, Superintendent of the US Naval Observatory, is pictured in the middle, again despite the fact that there’s no record of his attendence.  This is interesting, because Maury was a rival of many members of the Scientific Committee, including Alexander Bache.  Was this a jab at the Scientific Committee?

A guide and a full list of the identified attendees after the jump:

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Skywatch Line for Friday, May 6, through Sunday, May 8, 2016

This is Dudley Observatory’s Skywatch Line for Friday, May 6, through Sunday, May 8, written by Sam Salem.

On Friday, the Sun rises at 5:43am and sets at 8:02pm. The New Moon occurs at 3:30pm, this afternoon, and sets a few minutes before sunset, around 7:58pm. On Saturday, the New Moon sets at 9:10pm, try to catch the hairline crescent Moon twenty or thirty minutes after sunset, just a few degrees above the west-northwest horizon, Aldebaran is a few degrees above or upper left. Binoculars will help finding the 28 hours young Moon.

Jupiter reaches its transit altitude around 8:55pm on Friday and sets around 3:30am the next day. Tonight is the last chance to see a double shadow transit on Jupiter this apparition. Watch the two shadows on Jupiter as both Callisto and Io cast their tiny black shadows onto Jupiter’s sunlit face from 12:38 to 1:42 am tonight. Io’s shadow joins Callisto’s on the Jovian disk around 12:38am. Callisto’s shadow leaves the planet around 1:42am.

On Friday, Mars rises around 9:36pm, reaches its transit altitude around 2:17am and sets shortly after sunrise. Mars is entering its closest two-month charm in a decade. Blazing upper in constellation Scorpius, as it climbs higher, you’ll find Antares below it and Saturn to its lower left. Mars continues to grow in diameter as Earth continues to approach it. Mars will come to opposition on the night of May 21–22. For several days around its closest approach to Earth on May 30th, it will reach its largest since 2005.

The return of bright globular clusters to the evening sky is a signal that summer is just around the corner. This moonless weekend provides a good opportunity to search out for one of the globular star clusters that has gone on to become one of the best-studied objects in the night sky. Messier Object 3 (M3 or NGC 5272) is considered by amateur astronomers to be one of the finest clusters. As darkness arrives, M3 is in prime position nearly overhead. M3 is located in the northern starless space of constellation of Canes Venatici on the border with Boötes. The easiest way to pin down M3 is to draw an imaginary line connecting the stars Arcturus and Cor Corali. M3 is situated a little less than half way from Arcturus. The cluster is an easy catch in binoculars, which show it as a slightly bloated, fuzzy “star.” With a small telescopes used at moderate magnification you will start to resolve individual cluster members, and the view in an 8- or 10-inch scope can be spectacular. In 1764, Charles Messier logged M3 as a “Nebula without star”. With his small telescope, rather like the finder scope of a modern amateur telescope, Messier could not resolve M3 into stars.

Mercury will make its daytime transit across the Sun’s face on Monday. You can join the Dudley Observatory at miSci for this special event on Monday from 9am—3pm. See the link below. Special telescopes will be set up for safe solar viewing, hands-on sun-themed activities throughout the gallery, and a live stream of the transit. The entire transit is visible in Eastern North America. Don’t miss it as the next transit of Mercury won’t occur until 2019.

Skywatch Line for Monday and Tuesday, May 2 and 3, 2016

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, May second and third written by Joe Slomka.

The Sun sets at 7:57 PM; night falls at 9:49. Dawn breaks at 3:54 AM and ends with the Sun rising at 5:46.

By civil twilight, only one planet, Jupiter is easily seen, at minus 2.2 magnitude. Jupiter has already risen by sunset; it is best observed at about 9:10 PM. Days are growing longer, so opportunities for spotting shadows on Jupiter are growing slim. However, the Great Red Spot, a giant storm on Jupiter, is visible to telescopic observers at 2:09 AM, Wednesday. Jupiter sets at 3:42 AM.

Mercury is also in the western twilight sky. However, it is quite low, about three degrees high, and dim, only third magnitude. This poses a challenge for the observer, who needs an unobstructed horizon to even try for success. Mercury sets at about 8:52 PM, and is preparing for its Monday, May 9thtransit across the Sun. The Dudley Observatory and miSci will have telescopes and other instruments that provide safe ways to view the Sun and Mercury.

Mars, Saturn and the star Antares make their appearance at Midnight. Mars rises first, at 9:50 PM in Scorpius. Mars is also preparing for its own special event – its opposition. Every two years, Mars approaches Earth. This time it is the best in eleven years. As May begins, it is retrograding, moving westward. During the month, it steadily becomes brighter, and larger in our instruments. Binocular and telescopic sky watchers are beginning to see details on the Martian surface. The Albany Area Astronomers will host star parties, weather permitting, this month. The public is invited to see Mars up close. Mars is best seen at about 2:30 AM and sets during daytime.

Saturn, in Ophiuchus, follows Mars a half-hour later early in the month; later, due to Mars’ retrograde motion, it lags to an hour behind. Saturn, also, is becoming brighter and larger in our eyepieces. It will have its own opposition in early June. The Saturnian rings are tipped almost to maximum for our enjoyment. Depending on telescope size, several of Saturn’s 62 moons are visible. Astronomy magazines, websites and apps assist the viewer in identifying them.

Saturn, Mars and Scorpius’ brightest star, Antares, fly in a triangular pattern all month. However, again due to Mars’ rapid westward motion, the gap between Mars and Saturn increases.

Neptune rises in Aquarius during Astronomical Dawn. It lies low on the eastern horizon, appears at about eighth magnitude, and disappears as the sky brightens.

The Moon rises at 3:59 AM Tuesday, it emerges in Pisces and blazes at minus seventh magnitude. It looks about 16 percent illuminated. Wednesday, it rises in Cetus at 4:35 AM, shining at minus 5.1 magnitude and only 9 percent illuminated. Wednesday finds the Moon only six degrees above the eastern horizon. This is the last easily seen Old Moon of this lunar month.

Skywatch Line for Friday, April 22, through Sunday, April 24, 2016

This is Dudley Observatory’s Skywatch Line for Friday, April 22, through Sunday, April 24, written by Sam Salem.

On Friday, the Sun rises at 6:02am and sets at 7:47pm. The full Moon occurs at 1:24am on Friday. The full Moon that appears in April is called the Pink Moon. This name came from the herb moss pink, or wild ground phlox, which is one of the early spring flowers. It is also known as the Sprouting Grass Moon, the Egg Moon, and the Fish Moon. Early Colonial Americans used these names as they learned them from the local Native Americans. These names usually describe some activity done by those tribes during that time in their location as they used to track the time by observing the seasons and lunar months.

The Moon rises at 8:17pm on Friday, 9:13pm on Saturday, 10:09pm on Sunday.

Full Moon is out all night at the peak of this year’s Lyrid meteor shower. The annual Lyrid meteor shower is active each year from about April 16 to 25. This year the peak of this shower, which tends to come in a burst and usually last for less than a day, is expected to fall on the morning of April 22nd under the glaring light of the full Moon.

Mercury remains well-placed low in the west-northwest in twilight, but it’s fading fast.

On Sunday, around midnight watch Saturn and the red supergiant star Antares follow the waning gibbous Moon and Mars over the southeast horizon

Look high in the West for Pollux and Castor lined up early at night. The heads of the Gemini twins, Pollux and Castor, form the top of the Arch of Spring. The two ends of the Arch are Procyon to their lower left, and brighter Capella farther to their lower right.

Arcturus is the brightest star in the east. Spica shines to its lower right. To the right of Spica is the four-star constellation Corvus, the Crow of Spring. It is recognizable for its compact, boxy shape. In Greek mythology, Corvus was seen as the cupbearer to Apollo, god of the Sun.

Friday is the Earth Day. It is an annual event celebrated on April 22, on which day events worldwide are held to demonstrate support for environmental protection. It was first celebrated in 1970. While the Earth Day was first focused on the United States, it is now coordinated globally and celebrated by more than 193 countries each year. There are many ways to celebrate the Earth Day. You could plant a tree, make a meal with locally grown vegetables, clean up trash in the neighborhood, or save power.