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 conveyance by land and water, we deem them and their visionary schemes unworthy of notice....  The gross exaggeration of the locomotive steam engine may delude for a time, but must end in the mortification of all concerned....  It is certainly some consolation to those who are to be whirled, at the rate of 18 or 20 miles per hour, by means of a high-pressure engine, to be told that they are in no danger of being sea-sick while on shore, that they are not to be scalded to death or drowned by the bursting of a boiler, and that they need not mind being shot by the shattered fragments, or dashed in pieces by the flying off or breaking of a wheel.  But with all these assurances, we would as soon expect the people of Woolwich to suffer themselves to be fired off upon one of Congreve’s ricochet rockets, as trust themselves to the mercy of such a machine going at such a rate.”

These words, strange and ludicrous as they seem to us, but tersely expressed the general opinion of the day; but fortunately the clear head and the undaunted will persevered, until success was at last attained, and the magnificent railway system of the present, which has revolutionized the world, is the issue.  And the results are almost overwhelming in their magnitude.  Here, in Great Britain alone, 654,000,000 people travel annually.  There are 14,000 locomotives, and the rolling stock would form a train nearly 2,000 miles long; while the number of miles traveled in a year by trains is more than 10,000 times round the world; and the passengers would form a procession 100 abreast, a yard apart, and 3,700 miles long.