Sunday, June 10, 2012

The Telescope Maker's Art

I'm way behind on posting.  This one is from way back in April from our trip to Columbia, South Carolina.  Besides the primary reason to go to visit my mother-in-law Betty, another was that I had heard from her that they had a display of antique telescopes from the collection of local amateur astronomer and collector Bob Ariail.  We actually posted about Bob, and the early stages of that optics collection a few years back, when we last travelled there with friend Roger Ceragioli.  Shown here at left are 2 placards of introduction to the display.

The South Carolina State Museum is an amazing place.  It is located in a 120 year old textile mill, the first mill to be fully electrically powered at the time.  It is a huge space, 4 floors of displays and artifacts of art, history, science and technology.  There are visiting and always changing exhibits - they were about a week away from opening a "Titanic" artifact exhibition, and when we were there last time there was a major Napoleon display.  The Bob Ariail exhibit is the first part of a major expansion of the museum for a planetarium and observatory, which will feature an Alvin Clark 12 3/8" refractor as it's centerpiece - also donated by Bob, I believe. 

Besides the on-site display, there is also a digital version that can be accessed on line for those of you who cannot travel there in person.  The exhibit was spacious and displayed a good variety of telescopes from the last two and a half centuries.  Interestingly, the collection includes a 12.5" reflecting telescope that Bob himself made 35 years ago and used for making over 10,000 estimates of variable star brightnesses for the AAVSO.  While Bob's own telescope was made by his own hand of plywood, the antique telescopes from the 1700s into the 1900s were made by true artists in the materials of the day - fine brass, chrome and wood.  It was amazing to see the craftsmanship of these devices - my only regret is that we were not able to look through them.  Perhaps in the expansion project they will figure out a way to allow such intimate contact with these historical artifacts.

I'm a big fan of giant binoculars, owning a not-so-antique pair of 20X120 Japanese battleship binoculars now approaching 70 years old.  I was amazed to find not one, but two pair of Zeiss instruments from a couple decades earlier.  I was also amazed to see an illustration of one of these at the Grand Canyon at Kolb Brother's Studio, where they still sit objectives pointing down dejectedly, eyepieces missing.  I didn't have a clue they were Zeiss, but the illustration seems to support it (seen in the background in the image at left). The pair seemed a natural for a stereo pair also, so have included it at right.  These are a "cross-eyed" viewing pair - click to enlarge, then cross your eyes slightly to view the right image with your right eye and vice-versa.  There will be a center image that will display the stereo effect.

Shown here also are some of the earliest achromatic telescopes - two-lens objectives of differing glasses that correct chromatic aberrations of singlet lenses.  At left the image shows a Dollond telescope from 1780.  From about the same time period at right is a Gregorian reflecting telescope from 1760.  The reflecting telescopes didn't have the color error of the early refractors, but were difficult to make well because of speculum mirrors and small diameters available at the time.

As someone associated with optics and astronomy the display was doubly interesting to me, but the wide variety of the instruments even kept Betty and Melinda interested while I hung around taking picture after picture...  But as I mentioned earlier, the craftsmanship really stood out - the engraving and attention to detail was amazing.  If we could only look at a distant horizon scene and watch the troops of Sherman approach...  Oops - that is a different section of the State Museum!

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