there forms an equal volume of carbonic acid, and the contraction is the
half of CO. Thus, to analyze CO, a portion of the liquid is removed from
the burette, then caustic potash is allowed to enter, and the process
goes on as explained above.

The total contraction resulting from combustion and absorption,
multiplied by two-thirds, gives the volume of the oxide of carbon.

The hydrogen and oxide carbon may thus be quantitatively analyzed
together or separately.--_Revue Industrielle_.

* * * * *




THE "UNIVERSAL" GAS ENGINE.


The accompanying engravings illustrate a new and very simple form of gas
engine, the invention of J. A. Ewins and H. Newman, and made by Mr. T.
B. Barker, of Scholefield-street, Bloomsbury, Birmingham. It is known as
the "Universal" engine, and is at present constructed in sizes varying
from one-eighth horse-power--one man power--to one horse-power, though
larger sizes are being made. The essentially new feature of the engine
is, says the _Engineer_, the simple rotary ignition valve consisting of
a ratchet plate or flat disk with a number of small radial slots which
successively pass a small slot in the end of the cylinder, and through
which the flame is drawn to ignite the charge. In our illustrations Fig.
1 is a side elevation; Fig. 2 an end view of same; Fig. 3 a plan; Fig. 4