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The Polar Museum: news blog

The mystery of “The Black Goggles”

While working through all the objects with Antarctic associations, we came across these:

Z238

They are described in the catalogue as “goggles” but they are definitely odd. The shape is completely unlike any other goggles we have ever seen, and they don’t look practical to wear. Even more unusually, the lenses are clearly magnifiers. All the rest of the Western style goggles in the collection (and we have over 70 pairs) have flat lenses with no prescription. Actually it makes you wonder what explorers with poor vision did before contact lenses, because you couldn’t fit glasses underneath snow goggles. Presumably they often couldn’t see very well outdoors.

Intrigued, we decided to ask an expert about the lenses in our black “goggles”. Are they prescription lenses, or are they meant for something else?  Luckily we have an expert very close at hand, namely Andrea Clamp from Clamp Optometrists in Regent Street.  She came over to the museum to examine the “goggles” with some specialist equipment. First she used a lens measure to work out the curvature of the lenses:

photo (2)

This showed that they are both identical, and are curved on the inside and outside to a similar degree (“biconvex lenses”). Then Andrea placed the lenses into a focimeter to work out their power and focal length:

photo (1)

This showed that the lenses both have a focal length of about 25cm and would magnify anything that distance away to about twice it’s natural size.  Andrea was impressed by the quality of the lenses, which have no distortions whatsoever.  The company which made the “goggles” was Dallmeyer, who were famous for camera lenses.

To an optometrist like Andrea it is quite clear that the “goggles” are not prescription goggles for an individual.  Instead it looks as though the “goggles” are intended as magnifiers to help with a particular task.  So the question is, what are they for?  Theories we are investigating include that they are an accessory for photography, part of a stereoscopic viewing system or maybe viewers for cartographers….  If you know what they are, please let us know!

There is a chance to get up close and personal with more of our goggle collection this weekend at Conservation Conversations, a Science Week event at the Fitzwilliam Museum on Saturday and Sunday, 2-4pm.  It is a drop-in session with no need to book.  Just come along and have a chat with us – we will be delighted to meet you.

 

Sophie

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