128 SECTIONAL ADDRESSES. 
the others being Merrifield, Galton, and Rankine. The committee recom- 
mended experiments on actual ships, but Dr. Froude dissented and gave 
it as his opinion that model experiments were of value and were much 
cheaper to carry out, describing some he had made in 1867. In 1868~9, on 
the suggestion of Sir Edward Reed, then Chief Constructor, the Admiralty 
agreed to bear the cost of the construction and the working costs of the 
tankat Chelston Cross, Torquay. This tank started work in 1871, Dr. Froude 
acting as chief, and he gave his services gratuitously as long as he lived. 
On his death Mr. R. EK. Froude took over charge, continuing and expanding 
his father’s work. The results were freely communicated by him, with 
the full consent and encouragement of the Admiralty, to the Institution 
of Naval Architects in a series of valuable papers. The Torquay tank was 
ultimately dismantled and transferred to Haslar, where the good work 
is continuing. 
From the Froude tanks great benefits have flowed. I shall leave 
Mr. Mumford to show in detail the effect of these establishments on the 
design of ships and their propellers. Probably no one is more qualified to do 
so, with nearly fifty years’ experience in experimental tank work. He 
joined the staff at Torquay in 1878, after having been trained as a naval 
architect in Devonport Dockyard, and took charge of the Dumbarton 
tank in 1882, when the first private one was built at the suggestion of 
the late Wiliam Denny, than whom perhaps no private naval architect 
had so much influence on the profession in such a short life; he died in 
1887, at the age of thirty-nine. I shall confine myself to giving one 
example of the benefit of the tank. 
In 1888 the Prince ' Henriette was built at Dumbarton for the 
Ostend-Dover service of the Belgian Government. The ship’s lines 
were developed in the tank and the paddle-wheels were fixed in size and 
position from trial runs with model wheels in the tank. She was 300 ft. 
-by 38 ft. by 8 ft. 6 in. draught, and the speed on Government official 
trial was 21.09 knots. The previous fastest paddle-boat, built in 1885 
at the same yard, was of the same length—300 ft. by 35 ft. beam, and 
draught 7 ft. 8 in. ; its speed was 15.01 knots. Thus within three years, 
and largely by the aid of the tank, six knots higher speed was attained 
on the same length. The original tank trials were made with the same 
beam as the older vessel, viz. 35 ft., but only 194 knots was predicted. 
It was then suggested by the tank staff to try 38 ft. beam, thus fining 
the lines, when an extra knot for the same power resulted. Of course, 
every effort was made. both in the hull and in the machinery, to economise 
weight and provide the highest possible power. In the compound two- 
cylinder diagonal machinery, designed by the late Mr. Walter Brock, cast- 
steel entablatures, wrought-steel guides, and single eccentric valve gear 
were used ; the boilers were Navy type, straight-through tubular, working 
under forced draught in a closed stokehold. Still, without the tank experi- 
ments neither the naval architect nor the engineer would have had the 
confidence to proceed or to undertake the onerous Government guarantees 
demanded. 
But before tank trials were available there was a notable influence at 
work which was constantly inspiring the desire for higher and higher 
speeds in merchant-ships. I refer to the construction and development 
of high-speed launches, torpedo-boats and destroyers, with which the names 
