Professor Ph. Carl, of Munich. What led to the adoption of the device was
that, during last winter, the water supply in the neighborhood of the
Professor's laboratory was several times cut off without previous notice;
the result being the failure of the water needed for cooling the cylinder
of his Otto gas-engine. On inquiring into the matter, he discovered that
the same thing frequently occurred in other places where gas-engines were
in use; and this caused him to design a contrivance to put an alarm-bell
into action at the instant when the water ceased to flow, and so enable
any overheating of the engine, and injuries thereby resulting, to be
prevented in time. The arrangement (represented half size in the
accompanying engraving) is screwed down directly to the water outflow
pipe, R. Before the aperture of the pipe is a lever, with a disk on one
arm, on to which the issuing water impinges, thereby keeping the lever in
the position indicated by the dotted lines. The effect of this is to
break the platinum contact at C, and so interrupt the circuit of an
alarm-bell placed in any suitable position. Suppose the water ceases to
flow; the spring, F, comes into play, contact is made at C, and the bell
continues to ring till some one comes to stop it. It is almost needless
to remark that the disk, D, and the pin, E, are composed of insulating
material, such as vulcanite.--_Jour. Gas Lighting._

* * * * *




SOLDERING AND REPAIRING PLATINUM VESSELS IN THE LABORATORY.

By J.W. PRATT, F.C.S.