The Microfcope explained. xxxiii 
fcrew n, and Aiding the bar b, c, higher or lower; then 
by refixing the fcrew n, and turning the fcrew pq, 
you may obtain the true focal diftance of the magnifier 
then applied. 
Ivory Aiders and glafs plates, &c. may be laid acrofs 
the aperture ilk of the ftage. when the microfcope is 
in a vertical fituation, but when it is inclined as in fig. 
17. recourfe mud be had to the clip bed. No. 10. its 
Ihank d, a, is to be put into the focket 1 on one fide 
the ftage, and puftt’d down upon the Aider, glafs plane, 
&c. fo as to keep it from dipping off when the inftru- 
ment is inclined. 
A fmall fifti or frog may be tied on one of the glafs 
planes, or it may be confined thereon by the clip, No. 10. 
when the circulation of the blood is to be obferved. 
a, b, No. 11. are the nippers pointed at one end for 
different obje&s, or to receive on the pointed end the 
ivory cylinder, No. 12. for opake obje&s : this is to be 
applied to the microfcope, by putting the ftem c, into 
the hole m, fig. 16. 
There are fix magnifiers to this microfcope j one of 
them is reprefented at No. 5. another at No. 6. they 
are to be ferewed into the ring, f g. 
By means of the fhank fh, of the ring f g, which 
Aides backwards and forwards in the piece h z, and by 
the afiiftance of the joint at z, the magnifier may be 
brought over any part of the ftage, 1, i,kj the fcrew 
at y, will fix the magnifier, when it is found convenient. 
There are two filver fpecula to this microfcope, one 
of which is feen at No. 13. each of them contain a mag¬ 
nifying glafs ; their ufe is to illuminate opake objects ; 
thefe are to be ferewed into the underfide of the ring-, 
f O'. 
1 a 
No. 14. is a little barrel, with a lens to be ufed in 
the hand, or ferewed into the ring fg, 
d No. 7 , 
