Aerogels were first made by Kistler in 1931, but their application as transparent insulating mateials has attracted attention only recently. Silica aerogels, prepared by base-catalyzed hydrolysis and condensation of Si(OCH₃)₄, have been used in Chevenkov radiation detectors. Here, aerogels with index of refraction between 1.02 and 1.10 replaced the pressurized cryostatic gas systems with low indices of refraction. By exploring a wide range of process variables a base catalyzed tetraethoxysilane (TEOS) aerogel is produced of similar quality to one prepared from tetramethoxysilane (TMOS). -- AATA