December 19, 191! 



NATURE 



3i3 



hammer (lat. 6i c 7' N., long. io° 28' !■:.). Thi 

 isobyetals are drawn on two large-scale maps, which 

 show clearly the sharp variations in rainfall peculiar 

 to .1 mountainous country like Norway, the extremes 

 ing from 3400 mm. to 300 mm. of rain in the 

 year. 



1 111. importano ol the refractometer to the technical 

 chemist and physicist is being realised to an ever- 

 ising 1 ttent. I h determination of the refractive 

 index of .1 liquid (.111 he made quicklv and accuratelv 

 by means ol such an instrument, ihus affording valu- 

 able information as ii> the purit} of nils, fats, or drugs, 

 cent ration ol solutions. The investigation 

 of the optical properties of glasses and singh and 

 doubl; als ran be carried «>ui with the 



same instrument. It is highly satisfactory to learn 

 that British manufacturers are paying considerabli 

 attention to the construction ol refractometers. We 

 haw received from the firm of Messrs. Adam Hilger, 

 Ltd., a well-illustrated booklet describing their Abb< 

 refractometer with water-jacketed prisms for the 



I oi i' tractive indices from 1-3000 to 17 



The instruments are standardised, and not only the 

 mechanical, l>ut also the optical, parts are interchange- 

 able. \\ 1 have also received an account of the im- 

 proved type ol Vbbe refractometer designed and made 

 I >\ M gham and Stanley, Ltd. An interest- 



comparison is made between the features of this 

 instrument and the corresponding features of the 



German type, and il i- claimed that the increased 

 efficiency results in a saving of time of ahout 50 pei 

 cent, in the d< termination of refractive indices and 

 ions. 



Prof. Miles \\ ulker read an interesting paper to 

 the Institution of Electrical Engineers on December 5 

 mi the supph of single-phase power from three-phase 

 systems. In this country the advantages of three- 

 phase distribution of powei an thoroughly appre- 

 1. and man} of our large power-stations generate 

 1 his sj si, in. \i the presenl time 

 is .1 great demand in the Midlands for electrii 

 As these furnaces make 

 an excessive demand on the supply station, the com- 

 panii - the load taken by the furnaces must 



be a "balanced" load, and that suitable precautions 



taken to prevent resonance effects, which have 



sions caused a breakdown of the 



riot fully stated in 



the paper. Prof. Walker urged thi adoption of the 



-phase furnace. ! [1 the various 



methods that could be used to operate this furnace 



without upsetting the balance of the mains. Hi 



full particulars of ile design of a "rotating balancing 



sformer" for this purpose. The tests mad' 

 this machine show that its efficienc} was more than 

 This is a vi n satisfactory achievement. 

 We an not convinced, however, that ii is besl to 

 ii furnace when the supply is three- 

 phasi . \\ • know- several 1 sci llenl types of three-phase 

 furnace, and it is possible to connect them with the 

 three-phase transformer, so that the power factor on 

 primary windings is nearly unity. But even if a 

 single-phase electric furnace was essential, why not 

 coil, a transfi u 1 rotary con- 



denser separate!} ? There is no need to combine them 

 into a single machine. 



An interesting paper on the air supph to boiler- 

 ' b} Mr. Richard W. Allen at the 

 Institution 1 - and Shipbuilders in Scotland 



on Octobei Hi paper deals with the closed- 



stokehold system, and a large pari of ii is taken up 

 with the losses in the ducts and fan chambers, due 



Record- are given of experi- 

 NO. ^564. VOL. I02] 



ments conducted on new types of deck intakes, 

 weathei Haps, gratings, etc., designed in such a 

 manner as to securi stream-line flow in the currents 

 of air, and the results of experiments carried out on 

 older patterns of the same appliances are also in- 

 cluded. For example, a grating having bars of 

 rectangular section produced a drop in pressure of 

 from 0-065 in - t0 °' 22 KJ. of water, whilst another 

 having "stream-line" bars showed no perceptible drop 

 in pressure. The delivery through these gratings with 

 the fan running at the same speed was respectively 

 29,000 and 31,500 cubic ft. of air per minute. The 

 papei constitutes a valuable illustration of the ap- 

 plications of science to engineering design, and as 

 such is to be commended to any engaged in the design 

 and installation of fans. 



iiiK salvage of the St. Paid forms the subject of 

 an interesting article in the Engineer for December 6. 

 It may be remembered that this ship heeled and sank 

 in New York harbour in April of the present year. 

 I In hull settled upon the river-bed with the decks 

 marly vertical, and penetrated through the bed of 

 sih into the underlying hard soil. This rendered 

 the matter of the removal of guns, etc., 'a process 

 of considerable difficult) for the divers. Excavational 

 work was done by means of jets of compressed air, 

 thus blowing away the mud which had accumulated 

 round the guns. The ooze also entered the ship 

 through numerous open ports, and hampered the 

 work greatly. The dead-weight of the ship is about 

 13,000 tons, and the ship had to be rolled forcibly 

 back towards the normal upright position without 

 damage. This was accomplished by use of surface 

 pontoons, of A-frames attached to the uppermost side 

 of the ship, and of pumps which cleared the water 

 partially out of the ship. Four pontoons w-ere used 

 which exerted, on the rising tide, a lift of 1200 tons, 

 and produced a righting moment on the ship. The 

 rolling operation took about seven days to accom- 

 plish. The final operation comprised the pumping out 

 of the entire vessel. It is of interest to note that 

 the engineers responsible adapted the oxv-acetvli tie 

 torch for under-water service, and emploved it for 

 cutting drainage openings in various parts of the 

 ship. The entire salvage operation has been accom- 

 plished with conspicuous success. 



Tin: poisonous character of some cargoes of Burma 

 beans having been notice.!, it was suggested that the 

 I na Department of Agriculture should encourage 

 th' cultivation of varieties containing less hydrogen 

 cyanide than does Phaseolus lunatus. It has been 

 found, however, that imported Madagascar beans were 

 iiti'1 agriculturally to replace Pe-gya and Pe-byu- 

 gale, and that the prussic acid content increased dur- 

 ing two vears' cultivation. As bearing on the same 

 problem, tin- agricultural chemist of the Government 

 of Burma has studied tin- hydrogen cyanide content of 

 tin- commonest Burma bean, Pe-gya. The results ob- 

 tained are described in Bulletin Xo. 71) of the Agri- 

 cultural Research Institute, Pusa, by Messrs. F. J. 

 Warth and Ko Ko Gyl. It was found that the method 

 of estimating hydrogen cyanide by distillation (after 

 hydrolysis of the glucoside with acid) into sodium 

 hydrogen carbonate solution and titration with iodine 

 solution could not be used owing to the presence of a 

 substance which gives a slight iodine reaction. The 

 prussic acid was therefore estimated by conversion into 



Prussian blue, which was ignited and Wi rghed as 

 ferric oxide. Details of the method are given in the 

 bulletin. From about one hundred single-plant 

 samples collected in the cultivators' fields of the 

 Sagaing district ten samples of seed win -1 lected, 

 including two of the highest hydrogen cyanide con- 



