694 KANSAS CITY REVIEW OF SCIENCE. 
THE LICK OBSERVATORY TELESCOPE. 
The trustees of the Lick Observatory have finally closed the contract for 
the optical part of their great telescope. There has been considerable doubt 
whether a refractor or an enormous reflector would be selected, but the decision 
is in favor of the former. The object glass is to be three feet in diameter, and the 
Clarks of Cambridge, Mass., are to make it for $50,000. The mounting of the 
instrument is not yet provided for. Proposals will be obtained from the princi- 
pal instrument makers of Europe and this country. Probably the mechanical 
part of the instrument will cost as much as the optical. It may be three years 
before the telescope is finished. If the instrument proves successful, it will be 
the most efficient ever pointed at the heavens. Its power will exceed that of the 
Pulkowa glass by forty-four per centum, and it will be almost twice as powerful 
as the great telescope at Washington, which at present is the best of its kind.— 
Scientific American. 
METEOROLOGY: 
CLOUDS—LIGHTNING. 
PROF. S. A. MAXWELL. 
Clouds and lightning stand in relation to one another as cause and effect, 
therefore, in the proper consideration of the former subject, more or less mention 
of the latter must also be made. 
‘Lightning consists of an electrical discharge between cloud and cloud, or 
between a cloud and the earth, and sometimes between the upper and lower parts 
of the same cloud.” Such is the definition given by Prof. Henry to that wonder- 
ful electrical phenomenon, so often accompanying storms in the temperate and 
torrid regions of the earth—a phenomenon of such common occurrence as 
scarcely to need a definition, and yet so peculiar in its nature and action as to 
remain, even yet, to a certain extent unknown and unexplained. The discovery 
of the identity of lightning and atmospheric electricity was due to the genius of 
Franklin, who, more than any other philosopher of the eighteenth century, con- 
tributed valuable additions to science by his tireless researches and novel experi- 
ments. 
The electric spark in its passage through the air may be viewed under differ- 
ent conditions: hence arise those different names, —sheet-lightning, heat-lightning, 
chain-lightning, etc. If the spark is hidden by clouds, as it generally is during a 
storm, and a part of its light is reflected from the under side of the cloud, people 
call it sheet lightning. If seen during the serenity of a warm summer night, 
gilding the corrugated edges of a far-distant storm-cloud, or flashing from an 
apparently cloudless horizon, with gleams like the aurora—then, people say it is 
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