| This lens on a ball mount has been used for many years for lecture demonstrations. Neither date of purchase nor maker is known. It certainly has been part of the college's equipment since the early 1900s if not earlier. |  |
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| This lens on a ball mount has been used for many years for lecture demonstrations. Neither date of purchase nor maker is known. It certainly has been part of the college's equipment since the early 1900s if not earlier. | |