New video page

Over the past year, we have gone through the footage we captured last summer in our shoots with Linda Shettleworth and the Mann measuring engineFred Orthlieb and the telescope, and Roy Kilgard and the Millionaire mechanical calculator, and Melissa Sullivan of the New Media Lab has helped us turn them into a series of wonderful videos.

We shared many of them with the public at our exhibition opening and other events, but you can now check them out at home by visiting our new Videos page.  We also hope to make these videos available in the exhibition space from time to time.

A president, a professor, and the president’s wife go to Paris…Punchline: they come back with a telescope

Middletown CT, circa 1831…Astronomy is listed as a prospective course for Wesleyan students under the direction of Professor Augustus W. Smith, who will later become the President of Wesleyan University in 1852. Before students can actively engage in a college-level astronomy course, however, equipment is needed. How scientific equipment indeed reached Middletown, Connecticut from Paris, France is a curious story…


Sample correspondence. Image courtesy of Wesleyan Special Collections and Archives. Photo by the author.

In 1835 President Wilbur Fisk (who was known for his keen interest in astronomy), his wife, Mrs. Fisk, and Professor Harvey B. Lane journeyed to Paris specifically to purchase scientific equipment for the new university, including its first telescope. In Paris Fisk met Mr. Lerebours, a telescope maker, and expressed interest in purchasing a telescope for student and faculty use. After this initial visit, correspondence between Smith, Fisk, and Lerebours continued until Fisk purchased a refractor telescope with a 6” lens a year later for 6,000 franks and an additional 970 franks for shipping costs. And so, Wesleyan became the first university to own a 6” telescope! No other major university had any sort of 6” telescope; Yale University had a 5” telescope purchased in 1828.


This Bill of Sale indicates that Mr. Lerebours, the telescope maker in Paris, officially sold the 6″ telescope to Mr. Fisk. Thus, the 6″ telescope, currently mounted inside the Observatory, is titled “the Fisk Telescope.”

In the Wesleyan Special Collections & Archives there is not only an entire file on the 6” telescope but also copies of bill of sales receipts and purchases made by Fisk on behalf of the Wesleyan Astronomy Department.



Additional scientific equipment was sold to Mr. Fisk by Mr. Lerebour as indicated by the reverse side of the Bill of Sale. Image courtesy of Wesleyan Special Collections and Archives. Photo by the author.








Fisk Telescope Chronology

The “Fisk Telescope Chronology” allows us to track its path from 1835 to 1922. Image courtesy of Special Collections and Archives. Photo by the author.


When the Fisk telescope arrived at Wesleyan, it was placed in the back of Smith’s house at the intersection of College and Cross Streets, where it remained in use by students and faculty. The “Fisk Telescope Chronology” document accounts for its later 1866 placement to the site of Rich Hall (the ’92 Theater) in and then its movement to Observatory Hall in 1869.


Photograph of 1925 eclipse taken with use of the Fisk Telescope. Image courtesy of Wesleyan Special Collections and Archives.



Advance research using the Fisk telescope, however, was not performed until 1914 when Frederick Slocum became Professor of Astronomy. Slocum directed and initiated the fledgling parallax program; such a program dealt with the measurement of stellar objects and movements or position of stars. These measurements depended on the accuracy of the machinery used to record observations and the conditions of the atmosphere at specific times. The measurements were especially tedious, as they had to be recorded by hand pending further advancements in technology. The 6” telescope was not advanced enough to obtain accurate measurements, so in 1922 Wesleyan acquired the 20” in telescope specifically to determine stellar positions and build a more advanced parallax program. Even so, the 6” telescope was still used for documentation of the 1925 solar eclipse. I even found a printed photo of the eclipse made with the telescope while I was lurking around in Special Collections.

The 6” telescope moved again as the landscape of Wesleyan began to change in 1959. It was remounted and placed in a new dome that was west of the 20-inch refractor. From documents and letters in the Wesleyan SC&A, it seems that the 6” telescope went into dormancy from 1869 and 1925. Today, it stands on display, currently in the observatory, in all its glory. So, please feel free to stop by and sneak a peak!

Fisk Telescope mounted in the Van Vleck Observatory.

The Fisk Telescope in its current home at the Van Vleck Observatory.

Telescope Green and other custom paint colors for a custom telescope

What color is a telescope? And what does it matter anyway?


Although old photographs in black and white might not be the most convincing evidence, at least this photo shows that the telescope paint was dark. Photo courtesy of Wesleyan University Special Collections & Archives.

Back in the day (AKA 100 years ago), the 20-inch Van Vleck telescope was painted black. I believe the rationale was that astronomers wished to keep the space in the dome as dark as possible; naturally a dark paint was in order. More scientifically, the color black absorbs light. Stray light in the dome is something to consider and painting a telescope so that it can absorb stray light to the maximum seems rather logical.

Today the telescope is painted white–or more specifically, a slight off-white. The rationale here is that white reflects light. Because white does not absorb light like the color black does, a white telescope will be cooler than a black one. This is important to regulate the temperature of the instrument. The mount however is still kept at a dark hue. As for why the dome itself is painted white outside, well the story is not too different.

Now for all you extreme telescope enthusiasts out there who want to know the specific paint colors, I’m talking color codes and more here, you are in for a fun story.

Paint can lid for Dark Dakota Shadow

Paint can lid for Dark Dakota Shadow with Benjamin Moore color codes. Photo by the author.

A while back, Bill Herbst, his wife, and a consultant from the Wesleyan Art Department decided on the colors to paint the telescope: Dakota Shadow for the mount and North Star for the tubes. The Dakota Shadow was a bit too light, so a request was put in for Dark Dakota Shadow with no white added.

Paint can lid for Telescope Green with Benjamin Moore color codes.

Paint can lid for Telescope Green with Benjamin Moore color codes. Photo by the author.

Over the summer however, while working on the telescope restoration, Fred received a mis-mixed batch of paint. To remediate the error, the Cromwell Paint Spot shop named a new paint color–with the proper mix of green, yellow, black, and white–for Fred and put it in their system as “Telescope Green.”

Matt and I called the Paint Spot to investigate further. We spoke to a very nice sales representative who looked up the paint color for us. He didn’t recognize “Telescope Green” off the top of his head, but when we gave him the custom code he found it immediately! The rep said that the shop still has Telescope Green paint in stock, but because it is a custom color, we would need to bring in the can with the lid and the code to actually get the paint.

Fred points out the coats of paint on the mount. Photo(s) by the author.

Fred points out the multiple coats of paint on the mount. (Photo by the author)

This was the look on Fred’s face when Avi suggested the paint color could be called “T-Tauri Taupe.” Fred said, “I know what taupe is and this isn’t anything close!”

This was the look on Fred’s face when Avi joked the paint color could be called “T-Tauri Taupe.” Fred said, “I know what taupe is and this isn’t anything close!” In any case, Avi was working on the telescope restoration with Fred over the summer and he’s the one who tipped me off about Telescope Green in the first place. Thanks Avi! (Photo by the author)

Avi laughing

And to round out this post, here is a picture of Avi laughing, maniacally probably (not). Could he be wearing a t-shirt in the tone of Telescope Green?? And will this become the trendiest new paint color?? Only time will tell…

Teaching stellar parallax through the years

How far away are the the stars?  Answering this question constituted the major research effort of the Van Vleck Observatory for the bulk of the twentieth century. Using a technique called stellar parallax, the astronomers, plate measurers, and computers who worked at Van Vleck observed the heavens, made careful measurements, and performed calculations to determine the distances to stars.  While students were not actively involved in this process until the mid-twentieth century, the stellar parallax program was integral to astronomical instruction at Wesleyan, as we can see from the many pedagogical aids in our collection that relate to this technique.

What is stellar parallax?

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How the Van Vleck Observatory reflects environmental conditions

Before Van Vleck was completed in 1916, Wesleyan’s “observatory” was a tower mounted on a dormitory, containing few instruments with little research capability. Prior to that, the university’s effort at a building devoted to astronomy was little more than a shed.

Professor John Monroe Van Vleck, who taught astronomy at Wesleyan for 50 years, believed the university could do better. He envisioned an observatory with the facilities necessary to make an impact on the world’s understanding of the universe. In 1903, Van Vleck’s family donated more than $25,000 to the university for a new observatory and planning began, but Professor Van Vleck passed away before he could see his vision come to life.

In his stead, Wesleyan’s president Stephen H. Olin entrusted Frederick Slocum, the new astronomy professor, with supervising the observatory’s design. Slocum began a detailed correspondence with Henry Bacon, the architect charged with designing the observatory, to recommend the location, design, and technology of the building. Slocum was as determined as Van Vleck had been to see the Wesleyan observatory contribute valuable research to the scientific community. He was aware that it would not be easy, as New England’s cold, wet, and changeable climate was not ideal for astronomical observation. Slocum used a number of means—geographical, architectural, and technological—to overcome the challenges of doing astronomy in the relatively poor observational environment of New England.

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Letters from an old friend

My favorite part of putting together a history exhibit is getting to look through other people’s things. Certainly Frederick Slocum will not walk in on me as I’m hunched over his letters, and yet, I still feel like I’m intruding. But I’m not going to stop poking around, so let’s intrude together.

Slocum’s correspondence shows that he frequently allowed elementary school classes and intrigued guests into his observatory. He would let them look through the telescope, teach them about the moon and visible planets, and maybe leave them with some pictures of the stars. Classroom teachers in particular reached out to him from far and wide, from Flint, Michigan to Middletown itself. Though Slocum mostly published his work in academic journals, he clearly had an interest in making astronomy accessible to those outside of academia as well.

Amidst all of the letters to Slocum in our collection, one from a fifth grade class in Franklin, North Carolina stood out to me. The letter, dated October 31, 1934, is written in perfect grade-school cursive.

My Dear Prof. Slocum, We have been studying about the moon and wish to learn more about it. We don’t want to take your valuable time or inconvenience you, but if you have one new interesting thing that you can tell us about this heavenly body we will appreciate it very much. Just disregard this letter entirely if it seems impertinent. Yours sincerely, The Fifth Grade. Fifth grade students of Franklin, NC to Frederick W. Slocum, 31 October 1932. Frederick W. Slocum correspondence files, Van Vleck Observatory collections, Wesleyan University.

My Dear Prof. Slocum, We have been studying about the moon and wish to learn more about it. We don’t want to take your valuable time or inconvenience you, but if you have one new interesting thing that you can tell us about this heavenly body we will appreciate it very much. Just disregard this letter entirely if it seems impertinent. Yours sincerely, The Fifth Grade. Fifth grade students of Franklin, NC to Frederick W. Slocum, 31 October 1932. Frederick W. Slocum correspondence files, Van Vleck Observatory collections, Wesleyan University.

If the adorableness of their letter doesn’t hook you in enough, maybe this will: this fifth grade class’s teacher was Mrs. S. Edward Eaton, née Olive Eddy, who was Slocum’s own student in 1905 at Pembroke Hall. Enclosed with the students’ letter was her own, asking if the professor remembered her, and then immediately answering her own question with: “Of course you don’t.”

Mrs. Eaton was wrong. A mere two weeks later, Slocum responded, “I certainly do remember Olive Eddy and I am delighted to hear from her.” Enclosed with this letter to Mrs. Eaton was an extensive reply to her fifth graders’ queries. He included more than one interesting thing: he wrote about when the next eclipses were (down to the exact hour); what exactly to look at in the sky in order to see them; and also gave them a few photographs of the moon, Venus, the Van Vleck Observatory, and the observatory’s telescope.

He concluded,

I cannot easily tell you much about the moon at this distance, but if you can induce Mrs. Eaton to sew some wings on your shoulders so you can all fly up here, I will show you the moon through the telescope, and tell you all I know about it while are you looking.

Slocum’s writing and research proved that he knew how to address crowds steeped in academia, but this letter shows that he also knew how to appeal to children’s whimsy and blossoming interest in science.

Reflecting the past

Earlier this year, we came across some old scientific instruments kicking around Wesleyan’s Exley Science Center: microscopes and preparation plates, spirit levels, laboratory equipment, and, most interesting to us, a couple of small telescopes. What was interesting about this discovery was that several of the instruments dated back to the eighteenth century—a hundred years before Wesleyan was established in 1831.  What were they doing here?

We’ve since been trying to learn more about this collection of (mainly optical) instruments.  Inside their carefully crafted wooden cases, we found a few clues to their identities, if not their provenance.  Typewritten labels, which look to be from the 1970s or 1980s, suggest that these items may have been part of a small exhibit before. Newspaper protecting the more fragile elements dates from the 1960s.  Clearly these devices hadn’t been orphaned for too long—just long enough to be forgotten.

This Gregorian refracting telescope seems to date from the mid-1700s. An old handwritten label indicates that it was probably manufactured by Mann and Ayscough, who worked together from 1743 to 1747.

This Gregorian refracting telescope seems to date from the mid-1700s. An old handwritten label indicates that it was probably manufactured by Mann and Ayscough, who worked together from 1743 to 1747. Van Vleck Observatory collections, Wesleyan University.

The two telescopes in the collection are particularly interesting, given their age.  Both are reflecting telescopes, meaning that they use mirrors rather than lenses to focus light.  Reflecting telescopes were rare in the eighteenth century because it was very difficult to manufacture a smooth mirror whose reflective surface was on top of, rather than underneath, the glass.  Having the reflective surface below a refracting layer of glass distorted the image; overcoming this was a technical challenge for those seeking to manufacture telescope mirrors.  These two telescopes are thus very early examples of reflecting telescopes, from an age when refracting telescopes using lenses were the norm.

Gregorian reflecting telescope, G. Adams, 1795.

Gregorian reflecting telescope, G. Adams, 1795. Van Vleck Observatory collections, Wesleyan University.

These telescopes are also interesting in that they are tabletop instruments.  Each is equipped with its own stand, as well as a set of knobs for adjusting the angle and position of the tube.  This suggests that these were designed as gentlemen’s telescopes, and perhaps that they came to the university as a part of a faculty member’s personal collection.  So far, we have not been able to locate any records of their purchase or use, although it seems possible that they were used as teaching tools.

Today, most of the large telescopes crowning remote mountaintops are reflectors, and many of them contain not just one primary mirror but several mirrors arranged in an array.  (Most of these very large mirrors are made at the Mirror Lab at the University of Arizona in Tucson—you can visit and take a tour to see the process yourself.) In that basic sense, these two little eighteenth-century telescopes are akin to the massive research instruments of today, even though they appear similar to the observatory’s 20-inch refractor.

Seeing the heavens

By far and away, the oldest astronomical instrument is the human eye. And while astronomy remains a highly visual science, the way in which astronomical imaging occurs has changed a great deal over the centuries.

Near the end of his life, Galileo Galilei famously became blind. According to mythology, this was a result of observations he had made on the Sun (although this appears to be largely unsubstantiated). Regardless of the cause, his observations certainly affected his ability to do work, considering he observed by drawing what he saw through his telescope.

Carl Stearns (right); Robert T. Matthews, astronomy instructor; and a student. Image from Wesleyan University Vertical Files, Shared Shelf.

Carl Stearns (right); Robert T. Matthews, astronomy instructor; and a student working with the 20-inch in 1951. Image courtesy of Special Collections and Archives, Wesleyan University.

The advent of photography transformed astronomy in the late 19th century, allowing observers of the heavens to capture what the telescope saw automatically. Vision was clearly still important, but the kind of acuity that would have been necessary in Galileo’s day was less crucial. For instance, C. L. Stearns, one of Wesleyan’s professors of Astronomy in the early 20th century, was both nearsighted and colorblind. Indeed, his vision was poor enough that he was exempted from the draft during the First World War because of his eyesight. Yet his vision problems did not significantly hamper his ability to do astronomy, as is evident by his important work on stellar parallax.

Stearns observed in an era during which observations were recorded on photographic plates, taken from cameras that were attached to telescopes. It was the observer’s job to find the right stars and to focus the telescope, but he was not required to describe the objects in the field of view. As a result, good eyesight and the ability to distinguish between different colors was not as necessary in the 1920s as it was in Galileo’s time.

The 20-inch telescope with cameras and lenses attached. Set up for the January 24, 1925 total solar eclipse. Image from Wesleyan University, Vertical Files, Shared Shelf.

The 20-inch telescope with cameras and lenses attached. Set up for the January 24 total solar eclipse, 1925. Image courtesy of Special Collections and Archives, Wesleyan University.

Beyond meteors: showers and the history of astronomy

Visitors to Van Vleck Observatory may be surprised to find a shower located in one of the building’s restrooms. While it looks to have been decommissioned long ago—perhaps to the chagrin of those who bike to work here in the summer—its existence is at first puzzling. Why would there be a full bathroom in a space that appears to house just classrooms and offices?

Answering this question takes us back to the original plans for the observatory, and reveals how much the building and its uses have changed over the past century. Although nighttime observing and public events still take place regularly at Van Vleck, in the early 20th century the building would have been host to more astronomical activity after hours. This was due to the material realities and requirements of observation at the time: an astronomer had to be physically present in the dome to operate the telescope and camera. You can see that the first floor of the building includes not only computation rooms for the daytime activities of astronomical calculation, but a bedroom and bath for the convenience and comfort of the nighttime observer.

Floor plan of Van Vleck Observatory ca. 1916

Floor plan of Van Vleck Observatory, ca. 1916. Image courtesy of the Wesleyan University Department of Astronomy.

We can imagine what a night at the observatory might have been like by looking at the logbooks the astronomers used to record their observations. Positioning the telescope to view and track a particular star, exposing the glass plate to capture an image, jotting down notes on the weather and any problems—these were the methodical activities that filled an observer’s nights while the rest of the campus slept. When his duties were done—or perhaps if the sky clouded over or an instrument malfunctioned—he might be able to catch a few winks in the bedroom, or refresh himself with a rinse in the observatory bathroom before the next day’s labors.

Today, the room that once held a bed for weary observers is now an office, as are the computation rooms, and a new kind of room has appeared, where an observer can sit at a computer terminal and control the telescope from a place of warmth and relative comfort. The old marble shower in Van Vleck Observatory is thus an artifact of an earlier age of astronomy, before computer-controlled observations and remote data collection, when observers spent their nights at the telescope, quietly photographing the heavens.

When the world stopped: capturing the 1925 solar eclipse

Hartford Courant eclipse article

Headlines and artist’s image from Hartford Courant article, January 23, 1925.

The year 1925 started out with a bang for residents of the Nutmeg State: on the morning of January 24 a total solar eclipse would pass directly over Connecticut. Observatory directors across the country made plans well in advance to send parties of astronomers to observing locations with the most promising views. Area newspapers like the Hartford Courant, the Middletown Press, and even the New York Times hooked into the waxing excitement and perhaps contributed to the hullabaloo, too.

Solar eclipse plates. Courtesy of Van Vleck Observatory

Solar eclipse plates produced at Van Vleck Observatory (January 24, 1925). On display in the Van Vleck Observatory Library. Photo by the author.

On January 23, the day before the eclipse, the Courant released an article explaining the preparations in order. Hundreds of students and professors from Massachusetts universities were rolling into Connecticut by charter train. Public transportation in state, however, would cease. Trolleys would not be running. All businesses and commercial life was at a halt. The New York Stock Exchange even delayed opening until 10:15am—well after the scheduled ending of the eclipse. Crowds flocked to New Haven and Middletown, where the Yale Student Observatory and Van Vleck Observatory telescopes were in position to capture the event on film—and glass plates, naturally. Yale and Wesleyan’s observatories were two of just a handful of professional observatories in the northeast in the 1920s, so they eagerly played host to “eclipse parties” open to onlookers and “up-lookers” from around New England.

Solar eclipse plate. Courtesy of Van Vleck Observatory.

Photograph of 1925 solar eclipse from Van Vleck Observatory (January 24, 1925). On display in the Van Vleck Observatory Library. Photo by the author.

The total eclipse of the sun lasted about two minutes. Life resumed and the world moved on—literally and figuratively. The astronomers at Van Vleck had some great photos and some great data, too. Newspapers like the New York Times and magazines like Popular Astronomy published images of the eclipse made with the Van Vleck telescope. The observatory’s director, Frederick Slocum, even wrote up a report for Popular Astronomy on the eclipse and so the “Greatest Show on Earth,” as the Courant called it, became accessible to readers across the country.

As for the lunar eclipse two weeks later? Well no one really made much fuss about that. The Stock Exchange opened at its regularly scheduled time, and the folks at Van Vleck seem to have returned to their workaday routines.