88 EXPERIMENTS ON THE FROUDE. 
3 
The hull was built by Stearns and McKay of Marblehead, Massachusetts. 
Mr. Stearns gave personal attention to secure essentials for our purpose 
without wasting attention on non-essentials. 
The machinery was furnished by the General Electric Company and 
was placed aboard at their River Works at Lynn. The fitting and adjust- 
ment of the machinery and apparatus was done in the Charles River Basin, 
mainly by the mechanicians of the Institute, under the direction of Professor 
Harold A. Everett, who has had charge of the experiments during the 
summer months of 1910 and Ig1t. 
The Froude is indirectly propelled by a gasoline electric generating set 
and an electric motor with a chain-drive to the propeller shaft. Both 
generator and motor have separate excitation on the Ward-Leonard system 
which gives great facility and range of control, and provides for electric 
measurements of power. ‘Two measurements were made of the friction of 
motor, gear and propeller-shaft in 1910, when the boat was hauled up, by 
aid of a friction brake attached behind the propeller. In 1911 a friction 
brake was installed within the hull and brake tests were made with the 
propeller removed but otherwise under service conditions. 
In order to provide for ready determination of power by electrical 
methods during the season of 1910, the motor, before installation, was rated 
in the Electrical Engineering Laboratories of the Institute. A change in 
method obviated the necessity of rating for 1911. 
The water of the Charles River Basin is now fresh and there was very 
little fouling of the surface on the wooden planking of the boat, which was 
easily kept clean while afloat. To ensure a good condition of the surface 
the boat was hauled up and painted on July 21 and August 18, in the summer 
of 1910, and was painted twice for the summer of 1911. 
The proper draughts were permanently marked on the stem and stern- 
post and on both sides amidships, and the displacement was adjusted by 
ballasting. A compensating water-tank directly over the gasoline fuel-tank 
made it convenient to maintain the proper displacement and trim during 
the runs. Observations were made to ensure that the hull did not change 
shape. During runs for record, only the crew (Professor Everett and 
assistant) were aboard and in their proper places; the writer’s habit, during 
the first summer, was to be aboard when troubles were found or expected; 
during the second summer, his presence was not required. 
The boat is decked at bow and stern and has a house amidships, over 
the machinery. The steering-wheel and the electric-controller are on the 
starboard side abaft the house; two slender rods on the house enable the 
helmsman to align the boat accurately. The principal observer manoeuvers 
ee 
