December 23, 1909] 



NA TURE 



213 



Makeham's curve to the general population will be 

 of great interest to all statisticians. 



The publication of these lectures marks, we hope, 

 a turning-point in actuarial graduation ; it means that 

 the study of curve-fitting has now become a part of 

 the curriculum of the actuarial student, and a know- 

 ledge of frequency curves must be acquired before 

 the diploma of the Institute is won. This recent 

 development has enormously increased our power of 

 interpreting statistics, and Mr. Hardy will have done 

 actuarial science a great service if this book induces 

 the other members of his profession to follow in hi? 

 footsteps. 



MODERN ORDNANCE. 

 The E)i(;i)icering of Ordnance. By Sir A. Trevor 

 Dawson. The Gustave Canet Lecture, delivered at 

 the Twenty-fifth .Anniversary Meeting of the Estab- 

 lishment of the Junior Institution of Engineers, at 

 the Hall of the Worshipful Company of Fish- 

 mongers, June 30, 1909. Pp. iv + 53. (London : 

 Percival Marshall and Co., 1909.) Price 2s. 6d. 

 T T is generally understood that progress made in 

 ■*- the construction of guns, gun-mountings, explo- 

 sives, and projectiles during the last half-century far 

 exceeds that made in the preceding five hundred years; 

 but the causes of this great advance, and the methods 

 by which it has been accomplished, are not so well 

 known. In this small book, of little more than fifty 

 pages, the author has summarised the facts in a clear 

 .and interesting style, in a fashion perfectly intelligible 

 to ordinary readers. The descriptions of ordnance are 

 assisted by means of a series of excellent illustrations 

 representing ancient weapons as well as the most 

 recent types. 



The author is an eminent authority on the subjects 

 of which he treats, and he is a master in the art of 

 exposition. .As director in charge of the Ordnance 

 Department of Vickers, Maxim and Co., Sir Trevor 

 Dawson has been able to utilise the valuable training 

 and experience he had previously gained in the Royal 

 Navy, and to play a prominent part in recent ad- 

 vances. The value of the work done by him has just 

 been recognised by a knighthood, and many profes- 

 sional friends will join in congratulating him upon 

 this well-deserved honour. The Junior Institution of 

 Engineers was fortunate in obtaining the services 

 of such a man as their first lecturer and gold medallist 

 under the Canet bequest. 



M. Gustave Canet was a most distinguished French 

 ordnance engineer who received his principal training 

 in this country under the late Mr. Joseph Vavasseur, 

 and subsequently did much to advance the design and 

 construction of ordnance in his native country in asso- 

 ciation w'ith the great firm of Schneider and Co., of 

 ■Creusot. M. Canet was president of the Institution 

 of Junior Engineers in 1907-8; his death occurred at 

 the close of his term of office, and his family founded 

 a Canet Gold Medal as a memorial in accordance with 

 a wish he had expressed. No fitter tribute to his 

 professional eminence could have been paid than that 

 which the volume under review contains — a tribute 

 from a British ordnance engineer of the first rank to 

 NO. 2095, VOL. 82] 



the work which his French collaborateur had done in 

 improving ordnance for both sea and land purposes. 



The author has compressed and condensed a con- 

 siderable mass of material into the modest limits men- 

 tioned above, at the same time indicating the great 

 range and variety of the subjects affecting the design 

 of modern ordnance. He has also maintained his 

 sense of proportionate value in dealing with each 

 item. He shows how important have been contribu- 

 tions made bv metallurgists, chemists, and mechanical 

 engineers, and how essential has been the work of 

 each. Improvements in steel manufacture lie at the 

 root of advance in gun-construction and the making 

 of projectiles. The chemist has played a great part 

 in these improvements, and has devised much more 

 powerful " propellants " to take the place of gun- 

 powder, as well as high explosives which can be 

 safely fired from guns and be capable of working 

 havoc on an enemy's forces or ships. The mechanical 

 engineer has been no less useful ; indeed, it is his 

 lot to utilise all that metallurgists and chemists can 

 do so as to embody their latest discoveries in designs 

 for more powerful and accurate artillery, or in the 

 construction of more efficient gun-mountings. 

 Hydraulic, electric, and pneumatic methods of trans- 

 mitting and utilising power in connection with 

 ordnance all find a place and use, their relative value 

 and efficiency being differently assessed by different 

 authori'..ies. 



Sir Trevor Dawson states the case fairly, and records 

 his own opinions in many instances. For example, 

 what he says in regard to " wire-wound " and " solid- 

 steel " systems of gun-construction is well worth 

 study ; and equally so are his remarks on the advan- 

 tages and disadvantages of hydraulic or electrical 

 power for working and loading heavy guns ; or his 

 comparisons of nitro-glycerine and nitro-cellulose 

 powders. All these questions must be studied in the 

 original volume, as limits of space prevent even a 

 summarv being given of the author's conclusions. 

 Every reader of the book will gain a clear idea, not 

 merely of the ingenious devices now in ordinary use 

 for loading and working heavy guns or quick-firing 

 guns of moderate size and weight, but of the means 

 bv which present practice has been attained. Behind 

 the complete control and apparently easy handling of 

 the largest guns there lies a mass of complicated 

 machinery for the proper maintenance and use of 

 which highly trained staffs are necessary. The " sweet 

 simplicity " which prevailed before steam-power and 

 armour-defence came into use has entirely disappeared, 

 and cannot be restored. One comparison may be men- 

 tioned in conclusion. In 1864 the most powerful 

 12-inch gun was a muzzle loader, twelve calibres in 

 length, weighing about 23'5 tons ; its charge of 

 powder weighed 85 lb., the muzzle velocity of the 

 614 lb. projectile was 1300 feet per second, and it 

 could perforate 16 inches of wrought-iron armour at 

 the muzzle, or 8 inches at the maximum range of 6000 

 yards. The i2-inch gun of igog is a breech-loader, 

 fifty calibres long, weighing nearly 70 tons. Its pro- 

 jectile weighs S50 lb., the muzzle velocity is 3000 feet 

 per second, its perforative power is measured by 52 

 I inches of wrought iron at the muzzle, 37 inches at 



