3 6 Dr. Herschei/s Experiments on the Means 
half its thickness. It measures ,00237; the angle is o",2o6 ; 
and half of it 0A103. 
With 433,0 I see all the globules of a round form, and can 
by estimation divide No. 13 into two halves. The magnified 
angle is here 3' 29", o, but as its diameter could by estimation 
be divided into two parts, the round form of a globule some- 
what less might probably have been perceived, so that the 
magnified angle would perhaps not have much exceeded the 
quantity 2' 18", 9 that has been assigned before. 
After some time the weather became much overcast, and as 
the globules were placed over a cut hedge, the leaves and 
interstices of which did not reflect much light, they received 
the greatest part of their illumination from above. This made 
them gradually assume the shape of half moons placed hori- 
zontally. The dark part of these little lunes, however, did not 
appear sensibly less than the enlightened part, so that there 
could not be any thing spurious about them. 
By this experiment we find that the telescope acts very well 
with a high power, and will show an object subtending only 
o",484 so large that we may divide it into quarters of its 
diameter. 
4 th Experiment, with Globules of Pitch, Bee’s-wax, and 
Brimstone. 
I had before objected to sealing-wax globules on account of 
their dingy-red colour ; in the last experiment a doubt was 
raised with regard to the silver ones, because they were per- 
haps too glossy. In order to compare the effect of different 
substances together in the same atmosphere, I put up three 
