is increase in intensity was not
due to a greater consumption of oil, a determination was made of the
quantity of the latter consumed per hour. The Gagneau lamp, with the old
chimney, burned 62.25 grammes per hour, and with the Bayle 63 grammes in
the same length of time.

It may be concluded, then, that the increase in light is due to the
special form given the chimney. This new burner is applicable to gas lamps
as well as to oil and petroleum ones.

The effects obtained by the new chimney may be summed up as follows:
increase in illuminating power, as a natural result of a better
combustion; suppression of smoke; and a more active combustion, which
dries the carbon of the wick and thus facilitates the ascent of the oil.
The velocity of the current of air likewise facilitates the action of
capillarity by carrying the oil to the top of the wick. Moreover, the
great influx of air under the flame continually cools the base of the
chimney as well as the wick tube, and the result is that the excess of oil
falls limpid and unaltered into the reservoir, and produces none of those
gummy deposits that soil the external movements and clog up the conduits
through which the oil ascends. Finally, the influx of air produced by this
chimney permits of burning, without smoke and without charring the wick,
those oils of poor quality that are unfortunately too often met with in
commerce.--_La Nature._

* * * * *

MODERN LOCOMOTIVE PRACTICE.

[Footnote: Paper read before the Civil and Mechanical Engineers' Society,
April 2, 1884.]

By H. MICHELL WHITLEY, Assoc. M.I.C.E., F.G.S.

A little more than half a century ago, but yet at a period not so far
distant as to be beyond the remembrance of many still living, a
clear-headed North-countryman, on the banks of the Tyne, was working out,
in spite of all opposition, the great problem of adapting the steam engine
to railway locomotion. Buoyed up by an almost prophetic confidence in his
ultimate triumph over all obstacles, he continued to labor to complete an
invention which promised the grandest benefits to mankind. What was
thought of Stephenson and his schemes may be judged by the following
extracts from the _Quarterly Review_ of 1825, in which the introduction of
locomotive traction is condemned in the most pointed manner:

"As to those persons who speculate on making railways general throughout
the kingdom, and superseding every other mode of