solid and liquid bodies is a necessary consequence of the intensity of
gravity upon the earth. Upon a larger or smaller planet, a certain
number of solid bodies would pass to a liquid state, or inversely. Let
us return to the cyclostat. In default of gravity, centrifugal force
gives us a means of realizing certain conditions that we would find in
the laboratory of our magician. The cyclostat permits us to observe
what is going on in that laboratory without submitting ourselves to
forces that might cause us great annoyance. We have hitherto been
content to put poor frogs therein and study upon them the effect of
the central anæmia and peripheral congestion produced on their
organism by the unrestrained motion of the liquids carried along by
centrifugal force. The results, it seems, have proved very
curious.--_La Nature_.

* * * * *




MERCURY WEIGHING MACHINE.


We illustrate herewith a novel type of weighing machine. Hitherto the
weighing machines in common use have either been designed with some
kind of steelyard apparatus, upon which weights could be moved to
different distances from a fixed fulcrum, or springs have been so
applied as to be compressed to different degrees by different weights
put upon the scale pan, or table, of the machine. In other instances
more complicated mechanism is used, and various movable counterpoises
are usually required in order to balance the moving parts of the