Mean of the six runs, 20·818 knots per hour.
Mean steam pressure, 115 lbs. per square inch.
Vacuum, 23½ inches.
Mean revolutions of main engines per minute, 456.

"Trial of No. 420.

Min. Sec. Knots per hour.
1st run down occupied 2 33½23·452
1st run up"325½17·518
2nd run down"232½23·606
2nd run up"32117·910
3rd run down"23223·684
3rd run up"32417·647

Mean of the six runs, 20·636 knots per hour.
Mean steam pressure, 115 lbs. per square inch.
Vacuum, 24 inches.
Mean revolutions per minute, 466.

"The highest speeds were obtained by No. 419, during the third runs up and down, the mean of which give 21·12 knots, which is equal to 24-1/3 statute miles per hour, during which time the engines were making 470 revolutions per minute. At the close of the runs, the bearings were found to be in first-class condition, and there was not the least sign of anything getting warm during any part of the trials."

Spanish Torpedo Boat.—The following description of a torpedo boat built by this firm for the Spanish government, enumerating all the improvements that have of late been effected in the construction of such vessels by members of this firm, is taken from the Engineering under date the 21st of February, 1879.

"The alterations have a twofold character, and have reference to the arrangements for discharging the products of combustion from the furnaces and to those for steering the vessel. In brief, the boat is funnelless and is fitted with two rudders, one at each end. The main object in dispensing with the funnel is to enable the torpedo boat to approach as closely as possible to an enemy without being seen, a secondary, although still an important, consideration, being the absence of any obstruction to the steersman's view, such as a funnel on deck. The outlets for the smoke in the present instance are two ports, one on either side of the vessel, and placed about 15 feet in from the bow. Each of these smoke ports is fitted with a damper, and the smoke can be turned through either or both of the passages as desired. The control of these dampers is given to the steersman, who, on approaching an enemy, can direct the products of combustion through the port on the unexposed side of the vessel. The emission of smoke by day and of the glare and sparks by night are thus to a very large extent hidden from view, thus enabling the torpedo boat to approach very closely to the point of attack without being observed. The outlets are fitted with valves which are kept open by the blast, but which close on being struck by a passing wave. Should the vessel have to be out when a heavy sea is running the ports are closed, and a spare funnel is rigged up on deck, on one side. Although the smoke ports are placed forward in this boat, it is intended to place them aft in the next that Messrs. Yarrow build, as that arrangement will obviate the inconvenience at present experienced by those on deck from the heated gases of the furnace being carried along it at times by the wind, when on a certain course.

[YARROW'S TORPEDO BOATS.]