Title: The variable microscope

Identifier: QK475.H64 1770   (https://digital.lib.ecu.edu/1329)

Description: Sir John Hill's drawing of the variable microscope, 1770. In the 18th century, Hill wrote a treatise on the growth of timber using the new microscope as a scientific tool. Hill noted the increase in growth of tree rings as he made experiments on various types of trees. Reproduced from Hill, John. Construction of timber, from its early growth; explained by the microscope, and proved from experiments, in a great variety of kinds. (London: Printed for the author; and sold by R. Baldwin ... [et al], 1770). Plate 2.