Saturday, February 8, 2014

Journey through the History of Physics at the Greenslade Museum

Me (James) with Dr. Greenslade

A Visit to Dr. Thomas Greenslade’s
 Physics Apparatus Museum, Kenyon College

A view of Kenyon College campus

In Gambier, Ohio, north of Columbus, there is a small private liberal arts college called Kenyon College. There you will find the resident expert on physics apparatus, especially historic apparatus, Dr. Thomas Greenslade.  He is retired from the physics department and now he curates a large collection of physics apparatus from around the world, both historical and current but mostly from old-fashioned. The museum is housed in an addition to his home, right across the street from the Kenyon physics building.

A view of the museum, featuring tuning forks in the foreground, a telescope in the background 

Dr. Greenslade spent his career teaching physics at Kenyon College beginning in 1964, for over 40 years. He also travels as a guest lecturer across the country and around the world; he even spent a year teaching at the University of the West Indies in Jamaica. He has served frequently on the Committee on the History and Philosophy of Physics for the American Association of Physics Teachers (AAPT). He is currently Professor Emeritus of Physics at Kenyon College.

Before there were LCD projectors and Powerpoints, 
there was this projector (above) with homemade slides. 

Helmoltz Resonators

Vacuum pump (above) 
You probably have an electric vacuum pump in your classroom. 

Dr. Greenslade often writes articles for the American Journal of Physics and The Physics Teacher magazine; pictures of his historical apparatus collection appear in almost every issue of AJP. He is very knowledgeable and can engage in fascinating stories about how he acquired each piece and what its function is and whether or not it is a current style and how outdated it is.

I was grateful to Dr. Greenslade for giving me a tour of his museum and inviting me into his home. When I entered his home, I immediately saw physics apparatus displayed on shelves among a huge collection of books in his cozy home. The north wing of the house is a physics storeroom like you would find at a university, except this storeroom is annotated with small cards to describe each item. If you are able to understand what a Helmholtz resonator or a mannometric flame is supposed to do, you will feel right at home, although most physics teachers will not be familiar with all of this historic equipment.

Luckily, there is Dr. Greenslade who is willing, and perhaps the only one able, to explain the purpose of each device and its uses. On the top shelves, Dr. Greenslade displays classic and rare texts and many new apparatus (that were new to me, at least). Although I have studied the history of physics, there were still many apparatus present in the room with purposes that I did not even know existed. In the museum, there are old-style projectors, cameras, calculators or slide rules, and about 1000 stereographic images, many of which were made by Greenslade himself.

Dr. Greenslade has been cataloguing over the years and presenting images of each apparatus to the American Journal of Physics, perhaps to remind its readers of the creativity that has been displayed in demonstrating physics concepts throughout the centuries.

If there was a specialization of this collection, it is probably in the electromagnetic. In this area, the Greenslade collection seems to be the most extensive, particularly in cathode ray style apparatus, electric motor and generator demonstrators and wheatstone bridges from all of the suppliers for the past two hundred years or more. Just looking around you will find amusing things you wouldn’t find elsewhere, like an Indian ingot or several water-powered motors.

An ammeter and a mercury-dip slinky motor at left.

Dr. Greenslade is very gracious and gave me a guided tour of his house, where we viewed many other items in his collection, even his uncatalogued backroom set, which comprises two more shelves and includes many items that take a while to figure out what they are for, such as a mercury dipped motorwheel, a hall carriage, and an exploded rotating generator.

                                                         cathode ray tubes 

In the following picture, you can see a Chromoscope, 3-d, three color reviewer, and an X-ray generator…just in this picture alone, I can identify almost 100 apparatus.

On the left, you can see cathode ray tubes
In the middle, you can see a reflective tool used to measure 
the speed of sound in old-fashioned experiments. Below, a closer look.

Dr. Greenslade’s influence and correspondence is extensive in the physics teaching community, and everyone I know who reads physics magazines has been touched by his passion for historical physics apparatus. If you are in Ohio, I strongly advise you pay a visit to the Greenslade’s Museum and get in touch with the apparatus of our educational ancestors.

A lovely day for discussing physics apparatus

If you have an apparatus and you do not know what it is for, you should consult with Dr. Thomas Greenslade. Don’t take it out to the trash just because you don’t know what it is—Greenslade will know.

Greenslade's webpage


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