[Illustration:  FIG. 3—­APPLICATION OF THE BURNER TO A RETURN FLAME BOILER.]

In the experiment on the Flamboyante, the boiler was provided with but one apparatus, and the grate remained covered with a layer of ignited coal that had been used for firing up in order to obtain the necessary pressure of steam to set the vaporizer in operation.  This ignited coal appeared to very advantageously replace the refractory bricks, the role of which it exactly fulfilled.  It has been found well, moreover, to break the flames by a few piles of bricks in the furnace, in order to obtain as intimate a mixture as possible of the inflammable gases.

It is to be remarked that firing up in order to obtain the necessary steam at first is a drawback that might be surmounted by using at the beginning of the operation a very small auxiliary boiler.  The main furnace would then be fired by means of say a wad of cotton.  But, in current practice, if a grate and fire be retained, the firing will perhaps be simpler.

With but one apparatus, the pressure in the Flamboyante’s boiler rose in a few minutes from 6 to 25 pounds, and about a quarter of an hour after leaving the wharf the apparatus had been so regulated that there was no sign of smoke.  This property of the Dietrich burner proceeds naturally from the use of a jet of steam to carry along the petroleum and air necessary for combustion.  It is, in fact, an Orvis smoke consumer transformed, and applied in a special way.

It must be added that the regulating requires a certain amount of practice and even a certain amount of time at every change in the boat’s running.  So it is well to use two, and even three, apparatus, of a size adapted to that of the boiler.  The regulation of the furnace temperature is then effected by extinguishing one or two, or even three, of the apparatus, according as it is desired to slow up more or less or to come to a standstill.

The oil used by Mr. De Dosme on his yacht comes from Comaille, near Antun.  The price of it is quite low, and, seeing the feeble consumption (from 33 to 45 lb. for the yacht’s boiler), it competes advantageously with the coal that Mr. De Dosme was formerly obliged to use.—­La Nature.

* * * * *

[Continued from SUPPLEMENT, No. 622, page 9935.]

THE CHANGE OF GAUGE OF SOUTHERN RAILROADS IN 1886.[1]

  [Footnote 1:  A paper read before the Western Society of Engineers,
  June 7, 1887.]

By C.H.  HUDSON.

Many of the wheels that were still in use with the long hub were put into a lathe, and a groove was cut an inch and a half back from the face, leaving our cast collar, which was easily split off as before.  (Fig. 24.)