520 



NATURE 



[J^.>r, 13, 191 I 



to lack of financial support, Bcaufoy's experiments 

 wore never extended to ship-shape forms, and allhouKh 

 he insi>ted that such experiments would and did 

 determine the relative merits of models, his results 

 were ne{*lected by the naval architects of his time, and 

 only fitful attempts were made to revive interest in 

 mo(lel experiments until the time of Froude and 

 Rankine. 



Kankine in 1862 read his paper on waves, &c., and 

 in this and various papers published durinj^ succeed- 

 ing years he developed the application of what is now 

 known as the "stream-line theory" to all moving 

 bodies. 



Froude at this time, working on much the same 

 lines, had produced his well-known "law of corre- 



of the "Committee on Designs for Ships for War," 

 Froude conducted for the Admiralty the lowing ex- 

 periments on the Greyhound, which, in conjunct! :i 

 with the experiments made on a small model on. - 

 sixteenth the dimensions of the ship, comoletel'. 

 cated his theory, and led the Government to < 

 the experiment tank at Haslar, which was coinpi< : i 

 in 1879, where his son, R. F. Froude, has since sup< r- 

 intended the work. The applicability of results >! 

 model experiments to full-sized ships has more reccntl, 

 been verified by some experiments conducted by Mr. 

 Yarrow on a torpedo-boat, and published in 1883. 



Such tanks are now possessed by every nation thatjj 

 has any pretence to marine power, and by several off 

 oui leading shipbuilding firms, and the national experi- 



FlG. 2. — National I'hv^ical Laboratory Kxperimental Tank. Model-making Apparatu> 



spending speeds " ' — the true connecting link between 

 ship and models — and had verified it by experiments 

 on the river Dart with similar models varying in length 

 from three to twelve feet; and in his "explanations" 

 in tlie British Association Report of 1S69 he insists 

 o 1 tlie trustworthiness of experiments with models of 

 nilional size. At the suggestion of Mr. E. Reed 

 (afterwards Sir Edward Reed), a proposal and esti- 

 mate was made for an experiment tank, and this was 

 soon afterwards bnilt at Torquay, and became the 

 pattern on which all other tanks were modelled. 

 Shortly after this, in 1871, on the recommendation 



> Dr. Froude's eminciafion of this i.s as follows : — " If the ship be T> times 

 the dimension ' (as it is termed) of the model, and if the speeds are V'l, Vo, 

 V,^ . . . an'l the measured resistances are Rj, Ro. Rs . . . then for speeds 

 Vj^V], \/DV2, n'DVs ... of the .ship, the resistances will be D^R), 

 ly'Ro, D''R:i. . . . To the speed of model and ship thus related it is con- 

 venient to apply the term ' corresponding spf ed. " 



NO. 2172, VOL. 86] 



ment tank, which is now approaching completion :;t 

 Teddin-i'ton, is the sixteenth to be built. 



Suggestions for the establishment of a national ex- 

 periment tank have been put forward from time to 

 time by the council and various members of the Insti- 

 tution of Naval Architects, and among its chief advo- 

 cates has been Sir William White. It is due to the 

 munificence of Mr. A. F. Yarrow, a vice-president of 

 this institution, that the proposal has become a reality|i 

 the whole of the first cost being defrayed by him| 

 It will be largely supported by the leading shipowner* 

 and shipbuilders of the country, and will be open fof 

 tlie trials of any ship, but its chief purpose is to carry 

 out research work in fluid resistance and ship propuU 

 sion. The site chosen for the tank is at Bushv Park, 

 and it will be worked as a branch of the National 

 Physical Laboratory. 



