ZOOLOGY AND BOTANY, MIOEOSCOPY, ETC, 



639 



Galileo's Microscopes. — In the " Museo di Fisica," at Florence, are 

 two small Microscopes made wholly of brass, which Professor Meucci 

 (Curator of the Museum) informs us are considered to have been con- 

 structed by Galileo (cmte 1642), they having been handed down from 

 the days of the " Accademia del Cimento," always bearing the traditional 

 association of Galileo's name, and forming part of the collection of in- 

 struments belonging to that Academy at the date of its dissolution (1667). 

 By the courtesy of Professor Meucci we were enabled recently to photo- 

 graph the instruments, whence our figs. 98 and 99 are reproduced. 



The two Microscopes are of essentially the same design, differing 

 only in the shape of the scroll tripod supports, and in the fact that one 

 is provided with a cap over the eye-lens. 



As the lenses are wanting in both instruments, we are not able to 

 determine whether the eye-lens was of the convex (Keplerian) or the 

 concave (generally known as the Galilean) form. For focusing there 



Fig. 98. 



Fig. 99. 



are two screw adjustments, one for distancing the whole optical-body 

 from the object, and the other for regulating the distance of the eye-lens 

 from the objective, as in the Campani Microscopes we recently fignred.* 

 The absence of any kind of stage would imply that the examination of 

 opaque objects was principally intended. 



Apart from the late Professor Harting's conjecture regarding the 

 possible origin of the so-called " Janssen " Microscope, f and on the 

 supposition that these instruments were really made by Galileo, they 

 must be regarded as the earliest Compound Microscopes in existence. 



* See this Join-ual, 1886, p. 643, and 1887, p. 109. 

 t See this Journal, 1883, pp. 708-9. 



