November 15, 1901.] 



SCIENCE. 



7Q1 



river currents, constant changes of depth, 

 and many curves of short radius. 



Monday is usually devoted to electrical 

 engineering but, as already remarked, there 

 were but two papers approaching that 

 character this year. Mr. Killingworth 

 Hedges contributed a paper on ' The Pro- 

 tection of Public Buildings from Lightning,' 

 remarking that in 1888 the subject had been 

 discussed jointly by the Physicists and En- 

 gineers of the Association, but that there 

 had been no official report as to the effect 

 of lightning strokes upon buildings protected 

 by conductors since the Lightning Rod Con- 

 ference of 1882. In the discussion it was 

 said that architects could not be expected 

 to pay more attention to protection of build- 

 ings from lightning until engineers had 

 definitely decided what practice should be 

 followed, there being at present many con- 

 flicting views. - ' The Commercial Impor- 

 tance of Aluminium ' and ' Aluminum as a 

 Fuel,' were discussed respectively by Pro- 

 fessor E. Wilson and Sir Roberts- Austen, 

 F.R.S., the former considering chiefly its 

 advantages as an electrical conductor. 

 Mr. J. Dillon described a method of re- 

 cording soundings by photography, for the 

 use of engineers; Dr. Vaughan Cornish dis- 

 cussed the height and length of waves ob- 

 served at sea, and Mr. R. L. Jack showed 

 pictures of native bridges in Western China. 



Two reports of committees were pre- 

 sented to this Section. Professor H. S. Hele- 

 Shawmadea preliminary report for the Com- 

 mittee on Resistance of Road Vehicles to 

 Traction, from which it appeared that some 

 work had been done with a motor-car and 

 experiments had been made on an artificial 

 track so as to test the resistance of various 

 materials. Mr. W. H. Price reported for 

 the Committee on the Small Screw Gauge 

 that, while it had been recommended last 

 year that the thread of the British Associa- 

 tion screw-gauge should be altered in cer- 

 tain particulars, and the proposals had 



attracted much attention, yet so far the 

 recommendations had had no practical re- 

 sults. Professor G. Forbes explained a 

 portable folding range-finder, for use with 

 infantry, basedontheinstrument of Adie and 

 utilizing stereoscopic vision. After papers 

 by Mr. Mark Barr, describing his ingenious 

 machinesfor engraving the matrices used in 

 type-founding, by Mr. C. R Garrard, on 'Re- 

 cent Development of Chain Driving,' by Mr. 

 T. A. Hearson, on 'Measurement of the Hard- 

 ness of Materials by Indentation by a Steel 

 Sphere,' by Mr. E. T. Edwards, on ' The 

 Critical Point in Rolled Steel Joists ' and 

 b}^ Mr. J. W. Thomas, on ' Air Currents in 

 Churches ' the Section adjourned a day l^e- 

 fore the other sections. Notwithstanding 

 the paucity of papers, they were of fair qual- 

 ity and covered a wide range of subjects. 

 A. Lawrence Rotch. 

 Blue Hill Meteorological 

 Observatory. 



SCIENTIFIC BOOKS. X 



Smokeless Poiuder, Nitro- cellulose and Theory of 



the Cellulose Molecule. By John B. Bbrna- 



DOLT, Lieutenant U. S. Navy. N. Y., John 



Wiley & Sons. 1901. 



This work consists of eighty pages of new 

 matter and of one hundred and thirteen pages 

 of translation and reprints. The newly pre- 

 sented portion treats of : (1) Origin of the cel- 

 lulose nitrates ; the names by which they have 

 been sometimes designated ; and the meanings 

 that the author gives to the terms he employs ; 

 (2) to ' the earlier views as to nitro-cellulose 

 composition and constitution ' ; (3) to ' the con- 

 ception of progression in relation to compo- 

 sition and constitution ' ; (4) to ' solutions of 

 nitro-cellulose ' and ' theory of the cellulose 

 molecule.' It will be observed that in this brief 

 space the author has set for himself a most 

 ambitious program, especially as he applies him- 

 self to the solution of one of the unsolved 

 problems of chemistry and one which chemists 

 have regarded as presenting the most profound 

 difficulties. Naturally those chemists into whose 

 hands this book may come would turn at once 



