The eyepiece is placed at the end of a horizontal tube. In this way Amici intended to facilitate the observations. The rays coming from the objective, whose optical axis is vertical, are reflected by the hypothenusal face of a right isosceles prism placed immediately above the objective and are therefore sent in the horizontal direction corresponding to the optical axis of the eyepiece. The observation is possible either by transmitted or by incident light, using respectively light reflected by a large concave mirror or coming from a convergent lens placed at the end of an adjustable arm fixed to the microscope tube. A vertical parallelepipedic bar held by a steady tripod acts as stabilizer. The instrument, entirely of brass, is provided with rather sophisticated devices for horizontal and vertical adjustments. Moreover, a rotating horizontal disk having four holes of different diameter allows to restrict adequately the observation field by transmitted light. Overall height 36 cm. Unsigned. c. 1850.
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