BEffl 
PREFACE. 
III. A new application to the pyramidical 
camera .obfcura, by which means perfect draw¬ 
ings may be taken of all thofe beautiful micro- 
fcopic objects we are enabled to collect, by 
tracing their out-lines either with a pen or pen¬ 
cil, and that by any perfon who is not accuf- 
tomed to drawing. 
IV. We have given a defcription of the ca¬ 
mera obfcura, and have fhewn how to apply 
it in taking perfpedtive views of any landfcape, 
in three different forms of the fame inftrument, 
by which means faces may be out-lined to great 
exadtnefs, and pieces of Fill-life drawn from 
nature. 
V. We have likewife added a new compen¬ 
dious pocket microfcope, which is both fingle 
and compound. 
VI. We have alfo given a defcription of the 
heft kind of modern microfcopes now in ufe, 
that the reader may comprehend the utility of 
each, and thence be enabled to judge, which 
may fuit his purpofe bell. 
THE 
