Signedunsigned
FunctionThis is a stand designed to completely insulate a brass platform on top (missing on this one) from the floor. Earlier insulating stands were simply made of insulating material, but these still conducted some electricity because of the air's humidity that adhered to the insulator's walls. Mascart's insulator solves this problem by having the insulating column surrounded by completely dehydrated air. In order to accomplish this, strong sulphuric acid would be poured into the glass jar and stoppered. This sulphuric acid kept the air surrounding the glass column dry.
Historical AttributesProbably used at Blue Hill Observatory. (There is a small blank white rectangular sticker on the underside, probably a worn label that once identified this as coming from BHO. Compare 1998-1-0854, which has the same sticker but with the writing intact.)