The chamber is of all glass construction. A shallow glass cell, 17.9mm dia. x 0.4mm deep, is cut from plane glass plate and fused to a 75 x 25mm polished glass slide. Easy charging provided by two channels, 2mm x 5mm. Forms flat bottom chamber of approximately 0.1mL capacity. This instrument is for counting smaller plankters, using 43x dry objectives of approximately 0.65 n.a. and 4 mm e.f. The plane cover glass is 22 x 22mm and 0.16-0.19mm thick.

Photograph of 3850