April 7, 1910] 



NATURE 



"^11 



Relatively large quantities of nitrogenous and of potassic 

 manures are found necessary, phosphates being less needed ; 

 to meet this demand, potash salts and nitrate of soda are 

 now imported in quantity. Ten years ago there was 

 practicallj- no importation of these manures. 



A certain amount of the land has to be irrigated, especi- 

 ally that occurring on the leeward side of the high land 

 forming the interior of the island. On the windward side, 

 however, the rainfall is higher and irrigation is not neces- 

 sary. On the island of Hawaii itself most of the planta- 

 tions are unirrigated, but on the other islands irrigation is 

 very general. Here, also, useful help has been given by 

 expert engineers in ascertaining the cheapest effective w^ay 

 of obtaining the necessary water. 



SATIIRAL SCIENCE IN BENGAL. 



'T'HE annual report of the Asiatic Society of Bengal for 

 the year 1909 has now been published. We notice 

 that the society- celebrated its 125th anniversarj- on 

 January 15, 1909. The celebration took the form of an 

 evening reception held in the Indian Museum. Many 

 scientific, archaeological, philological, and historical exhibits 

 were shown, illustrating the progress and activities of the 

 societ}-. The council awarded the Barclay memorial medal 

 for 1909 to Lieut.-Colonel David Prain, F.R.S.. I. M.S. 

 (retired), in recognition of his biological researches. 



The total number of contributions to the societ}' under 

 the heading mathematics and the natural sciences was 

 seventeen. Commenting on these, the report points out 

 that Mr. Hooper's paper on Tamarisk manna shows that 

 the chief sugar in it is not mannite, but a saccharose. 

 Babu Bidhu Bhusan Dutta, in a contribution on the con- 

 stituents of the roots of Arisaema concinnum, Schott, and 

 A. speciosum. Mart., shows that these two famine foods 

 contain much nutriment, chiefly starch. Mr. B. L. 

 Chaudhuri directed the attention of the society to the 

 — osquito-larvae eating propensity of fish of the genus 



iplochilus, and asked for cooperation in making further 



-ervations. Several species of this genus of small fishes 

 are voracious feeders on the larvae. 



Babu Nibaran Chandra Bhattacharjee directed attention 

 :o the way in which Marsilia quadrifolia fruits only when 

 the water in which it has been growing recedes from it and 

 leaves it dry. Mr. H. Martin Leake's paper on Indian 

 cottons is of importance. His object is to breed early 

 cotton suitable for cultivation at Cawnpur, with the good 

 lint of the slow-maturing cottons; he has observed the 

 characters in bud development which lead to early or late 

 maturit}' in order to recognise such as combine with the 

 desirable quantities in the lint. Mr. E. P. Stebbing. in 

 a paper on the Loranthus parasite of the Moru and Ban 

 oaks {Ouercus dilatata, Lindl., and Quercus incana, 

 Roxb.), shows how destructive the parasite is to these 

 oaks in the neighbourhood of Naini Tal and in Kumaon. 

 Sir George King's " Materials for a Flora of the Malayan 



ninsula " has been continued. Accounts of the orders 



^iieraceae, by Mr. H. N. Ridley, and Verbenacejc. bv 



ur. J. Sykes Gamble, have been received. Mr. Burkill 



has diagnosed two varieties of the lemon oil grass, Cymbo- 



f^n^on Martini. Prof. P. Briihl has contributed a paper 



recent plant immigrants into Bengal ; 234 species are 



med by him; their origin is discussed and the causes 

 cr their introduction. America supplied 547 per cent, of 

 ^'Kse immigrants. 



T 



THE DEVELOPMEST OF ELECTRICAL 

 POWER AT NIAGARA FALLS.' 



HE development of electrical power at Niagara Falls 

 has long attracted widespread attention and interest. 

 Since the first installation upon the American side, descrip- 

 15 and discussions of its works and methods Rave been 

 ited a conspicuous place in technical records and the 

 - -ntific Press, but the fact is apparently less known that 

 tliere now exist at Niagara four more installations, each 

 larger than the pioneer plant, and one at least differing 

 from it to a very marked degree in the method in which 



1 From a paper entitled " An Account of a VLiit to the Power Plant of the 

 Ontario _ Power Co. at Niagara Falls." read before the Institution of 

 ■Mechanical Engineers on January 7, by Mr. C. W. Jordan. 



NO. 2 no, VOL. 83I 



the turbines are employed and coupled to the electrical 

 generators. 



The author, having paid a visit to Niagara in December, 

 1907, when exceptional opportunities were afforded him of 

 inspecting the whole plant of the Ontario Power Company, 

 takes the present opportunity of recording the following 

 notes, which may supplement the knowledge of the subject 

 hitherto available, especially so as, after the completion 

 of these notes, correspondence took place with the Ontario 

 Power Company with the object of eliciting further in- 

 formation, and photographs were received illustrating the 

 operations of the company. 



Scheme. — Briefly outlined, this company's development 

 comprises the taking of water from the Upper Niagara 

 River above the Horseshoe Fall, leading it through pipes 

 and penstocks to turbines in a station below the Fall, and 

 there utilising its energy for the generation of electricity, 

 which is transmitted to a second station on the hill above, 

 .ind thence distributed. There is a fall in level of 55 feet 

 in the rapids above the Horseshoe Fall, and to take 

 advantage of this the headgates are placed just above the 

 rapids. From the headgates three great steel and concrete 

 tunnels or conduits, laid below the surface of the Victoria 

 Park, will convey nearly 12,000 cubic feet of water per 

 second to the top of the cliff above the power-house, and 

 just beyond the Fall. Thence it will pass through twenty- 

 two steel penstocks in shafts and tunnels down and out 

 through the cliff to an equal number of horizontal shaft 

 turbines in the power-house below, which is situate on 

 the water edge immediately at the foot of the Horseshoe 

 Fall. From the generators, the electrical cables will pass 

 through tunnels to the twent^■-two banks of switches, 

 transformers, and instruments in the distribution station 

 on the hill above, and thence to the transmission lines 

 beyond, the whole installation, when complete, being 

 capable of an output of more than 200,000 horse-power. 



The intake works for the entire 200,000 horse-power are 

 now finished. One of the three main conduits is completed 

 and in use, while the portals and headworks for the second 

 and third tunnels are completed, and a portion of the 

 excavations made. Six of the twenti.'-two penstocks are 

 completed, and with their turbine-sets are at work, and at 

 the time of the author's visit the seventh was practically 

 completed. The distribution-station building is complete 

 for the switchboard of the entire twent>'-two units, for the 

 transformers of eight, and the other apparatus of fourteen 

 units, and is well ahead of the developments in the power- 

 house. 



The most import.^nt engineering features wherein this 

 latest company differs from its predecessors are the 

 arrangement of intake works, the design of main conduit 

 and spillway, the horizontal shaft turbine units, the 

 symmetry of arrangement of the whole, the centralisation 

 of control, and the protective isolation of the various 

 apparatus. 



Particulars of Niagara River and the Falls. — ^The total 

 drop in the Niagara River in its course of thirty-six miles 

 between Lake Erie and Lake Ontario is 326 feet, of 

 which 216 feet is in the Falls and the rapids immediately 

 above them. 



The American Fall is 167 feet high and 1000 feet in 

 width, while the Horseshoe Fall is 159 feet high and 

 2600 feet in width. The greatest depth of the river 

 immediately below the Falls is about 192 feet. It is 

 estimated that an average of 222,400 cubic feet of water 

 pass over the Falls each second. This is 25,000,000 tons 

 per hour, or about one cubic mile a week, and represents 

 a kinetic energv of nearly 5,000,000 horse-power. At the 

 headworks of the Power Co. the river is 3400 feet wide, 

 and flowing at an average velocity of about 8 feet per 

 second. 



Intake. — ^These works have been placed and designed, 

 not only to take advantage of the additional height of the 

 rapids as mentioned above, but also with special reference 

 to the ice difficulties, which have been the limiting factor 

 in the success of Niagara power. Cake-ice in enormous 

 Quantities floats down for weeks at a time from the Great 

 Lakes, and mush-ice is also formed in the rapids, primarily 

 bv the freezing of sprav and foam, and secondarily by the 

 disintegration of cake-ice. The latter trouble is avoided, 

 since the intake is in the smooth water just above the 



