Microscope /oroh-arin^ the XrisioTis onMifhcmoficol Instru mcnTs, 
as made iy l/C'Troughlon. 
Micrometer tor the Eye Tiess oEa Telescope. 
JitttV deJm . 
Xamy Eatlp, 
XondonFiMis'hed hvXontpnrm, Mtnet, Fees' Otyne, , 7 ime i "^1808. 
