SCIENCE 
IS 
KNOWLEDGE. 
A PRACTICAL 
KNOWLEDGE 
IS 
POWER. 
JOURNAL FOR AMATEURS, 
Copyright Secured. 
Vol. II. 
NEW YOEK, JULY, 1879. 
No. 
How I Made my First Telescope. 
BY W. B. HAERISON. 
OW much we need 
a telescope to 
show us all these 
wonderful 
things," said our 
teacher to the 
class in Astrono- 
my, at the close 
of a lesson, the 
subject of which 
was the planet 
Saturn. 
" Where can we 
get one," timidly 
asked one of the scholars. 
"I do not know," dreamily answered 
the teacher. 
"Does a telescope cost much," asked 
another, and the same dreamy " ' I don't 
know;' perhaps several hundred dollars," 
was the reply. The teacher then drew on 
the blackboard the form and combination 
of lenses of the common refracting tele- 
scope, closing with the remark that the 
principle of this telescope was very simple. 
"Why couldn't we make one then," I 
suggested, warmed by the subject, but a 
sneer as the class took their seats, told me 
that I had ventured too far. 
In the country school of New England, 
where this scene occurred, about thirty 
years ago, a half dozen of the larger 
scholars had formed a class in Astronomy 
and were using " Burritt's Geography of 
the Heavens " as a text book. They were 
plodding along somewhat blindly, with a 
teacher who knew but little of the science 
he tried to teach. 
The sneer that greeted my suggestion, 
stung pretty deep, and at the same time 
aroused my ambition to possess a tele- 
scope. The diagram drawn by the teacher 
floated before my eyes. The more I 
thought of it, the more simple seemed the 
instrument. Where to get the lenses and 
fixtures was the trouble. By a careful 
reading of the Natural Philosophy we then 
used (Olmsted's Kudiments), I learned 
that only two lenses need be used for the 
telescope I wanted. The image formed at 
the focus of the larger lens, being magni- 
fied by a smaller lens placed behind this 
image. It was all very simple, surely. 
I lay many, many evenings after this, 
looking at the stars through my bed-room 
window, and racking my brain how to get 
those lenses, for I was determined to have 
a telescope and to build it myself. In those 
days we had no Young Scientist to which 
we could refer for information, or to ask 
