Trial Trip of a British Built Torpedo Boat Destroyer for the Spanish Government
stern to stern and the engines of both set going, with the result that the screw-propelled Niger dragged the Basilisk backward a"ainst the whole force of her en gines at the rate, by log, of 1'466 knots an hour. These vessels were at the same tim e tried at different depths of immersion, and the conclusions arrived at from the results obtained were that, in similar vessels exerting the sam e amount of engine power and impelled by steam alone at their highest ob tainable speed, the screw is the
... , the screw is the most advantageous propeller at deep immer sions and the paddle wheel the best in the case of light and medium immersions. under the presidency of Commodore Triguiro, with whom were Lieutenants Ariba, Guimira, Vazguay, Naval Architect Taliso, Messrs. Thomson, Gordon and Haynes. The Pluton, which is one of a number of de stroyers building at Clydebank for the Spanish "ov ernment, is 225 feet long, and is thus somewhat lar"er than the latest class of British torpedo boat destroyers. She is therefore enabled to carry a considerably greater dead weight, the actual load on board during the trials being 73 tons. The results of the trial gave a mean sl?eed of 30'12 knots on the measured mile, and during [DECEMBER I I, 1897. The experiments deal with the number of memory images that can be stored up at a single trial, without allowing the subject time to rest. This is called in English the' mental span' of the memory. I have proposed for it the term 'faculte de prehension' Several successive investigations have already been made on the measurement of the lllemory for figures and syllables. These are localized memories, the deve lopment of which cannot be considered as a sign of the development of the other memories. We must, there fore, make many reservations in interpreting the conclusions to be drawn from these experiments. The ex periment may be made as follows: A series of figures is read to the subject at a regular speed (the speed used is in general two fig-Both the vessels were fit ted with four hun d red nominal horse power en gines. The propelling en· gines of the Basilisk were of the ordinary oscillating type and those of the Niger were a special kind of di rect acting horizontal en gine, having two pairs of cylinders; one pair being placed on each side of the main crank shaft, with an "TUG OF WAR" BETWEEN BASILISK AND NIGER, 1849. ures per second) and with out any special accentua tion. As soon as he has heard the series, the sub ject, having been told be forehand of the require ment, endeavors to repeat the figures without error and in the order ill which he heard them. The ex periment is repeated sev eral times, beginning with a small number of figures, e. g., four which any adult can give correctly: it is then increased to fi ve fi" ures, then to six, and so on, until a n u m b e r is reached which the sub ject can no longer repeat correctly. Care is taken to repeat each trial, and to allow sufficient inter· air pump between. Each piston had two piston rods I a continuou� run of one and a half hours a speed of working in different planes, one being above and one 30'02 knots was maintained. At the conclusion of the below the crank shaft, the rods of each pail' of cylin forced draught trial, the vessel was, according to con ders being connected to one crosshead, from which a tract, run for a further period of two hours under connecting rod passed to the crank and put its shaft natural draught, the speed attained being 22 " , knots, in motion. The air pump� were worked by a similar or T'O of a knot over the contract. During the tests arrangement to that by which the motion of the pis-there was a noticeable absence of vibration and the en tons was comlllunicated to the cranks, the whole form gines worked to the entire satisfaction of the Sp'l,nish ing one of the best examples of direct-action engines commission.