18 F. Waldo—Filling of Barometer Tubes. 
actually subtract from the snowfall, while increasing at the 
same time the annual liquefaction. The advocates of a warm, 
glacial climate have committed a most extraordinary oversight 
in failing to perceive that the moisture, which they would add 
to the atmosphere, can fall as rain only. Not until the air has 
discharged as rain all the moisture in excess of the quantity 
which saturates it at zero, can it begin to yield snow. This con- 
sideration alone ought to have deterred them from such a doc- 
trine and its mere statement might seem sufficient to refute the 
idea. But it has been deemed proper to investigate the sub- 
ject at some length, and to examine each component factor in 
its proper relations, in order to make ourselves sure that what 
seems to be a complete answer at the first glance, is still com- 
plete, however it may be tested in detail. 
Art. Il.—On the application of Wrights Apparatus for distilling, 
to the filling of barometer tubes; by FRANK WALDO, Computer 
0.0; 3.0. 
[Communicated by permission of the Chief Signal Officer.] 
this cock can be connected with the open end of the barometer 
tube to be filled, which latter will take the general position of 
the whole tube g of Professor Wright’s drawing. 
he rubber tube must be covered with melted sealing wax. 
The impure mercury in a should first be washed in acids and 
dried before introduction. At the beginning of operations a is 
full of impure mercury, but the rest of the apparatus contains 
only air. The Sprengel pump is set in motion and gradually 
exhausts the air from 4, c, d, e and the barometer tube, until no 
air bubbles can be seen in the running mercury of the Sprengel 
pump, and until the sharp click is heard when the drops of 
