latter from giving way to the traction of the threads, permitting it
thus to move only in the direction of their plane.

It will be seen that by this system two of the sides of the
parallelogram are capable of elongating or contracting through the
unwinding and winding of the silken thread on the drums of the two cog
wheels, which latter, gearing with each other, allow of the escape of
but the same length of the two threads.

It will be observed that in this system integration is effected by
forcing the pen to follow a certain direction, and that consequently the
curve does not depend upon the dimensions of the different parts of the
apparatus.--_La_ _Lumiere Electrique_.

* * * * *




APPARATUS FOR MANUFACTURING GASEOUS BEVERAGES.


The apparatus represented in the accompanying cuts is designed for the
manufacture of gaseous beverages, and is of Messrs. Boulet & Co.'s make.
Fig. 1 represents the apparatus complete, with gasometer and bottling
machine. Fig. 2 gives a vertical section of the apparatus properly so
called, including the producer, the purifier, and the saturator, all
grouped upon a cast-iron column.

[Illustration: FIG. 1. APPARATUS FOR MANUFACTURING GASEOUS BREEZES.]