244 



NATURE 



[July 12, 1900 



no vacuum can be formed ; the pressure will depend 

 only on the height of the column of water above the 

 screw ; the limiting velocity will be less than when the 

 screw remained free from air. 



The steering of screw steamers is dealt with in several 

 papers laid before the British Association ; three of these 

 are reports of a committee appointed in 1875 to investigate 

 the question. Of this committee Prof. Reynolds was 

 secretary. Briefly, their researches confirm the theory 

 he had advanced in a paper published in the En((ineer, 

 June 4, 1875, explaining the accident to the steamer 

 Bessemer, which had failed to enter Calais Harbour on 

 May 8 previously. 



Prof Reynolds pointed out 



"when a ship is stopping, the water will be following her 

 stern relatively faster than when she is moving uniformly, 

 and consequently that the effect on the rudder will be 

 diminished ; that the longer the ship the greater will be 

 this difference ; also that this effect is greatly increased 

 when a ship is stopping herself with her propellers, as 

 was the Bessetner, for since not only is the retardation 

 of the vessel much more rapid, but the water has a for- 

 ward motion imparted to it by the propellers, which 

 motion, if the propellers are near the rudder, may be 

 greater than that of the ship, in which circumstance the 

 effect of her rudder's action will be reversed." 



In the paper on the radiometer, " On the Forces caused 

 by Evaporation from, and Condensation at, a Surface," 

 the true explanation of its action is given in the con- 

 cluding paragraphs. The paper deals in the main with 

 the effects of evaporation and condensation in causing 

 motion, but near the end the author writes : 



"Since writing the above paper, it has occurred to me 

 that, according to the kinetic theory, a somewhat similar 

 effect to that of evaporation must result whenever 

 heat is communicated from a hot surface to a gas. The 

 particles which impinge on the surface will rebound with 

 a greater velocity than that with which they approached, 

 and consequently the effect of the blow must be greater 

 than it would have been had the surface been of the 

 same temperature as the gas." 



The longest paper in the collection is that on certain 

 dimensional properties of matter in the gaseous state ; 

 it contains the results of a number of experiments on the 

 thermal transpiration of gases through porous plates, 

 and an extension of the dynamical theory to account for 

 the phenomena. 



Enough has been said, perhaps, to show the interest 

 of the volume and the importance of the scientific results 

 it contains. It is got up in the admirable manner which 

 characterises the Pitt Press productions, and in form 

 leaves nothing to be desired. 



COUNT SCHEIBLER'S SPORTING TOUR. 

 Sette Anni di Caccia Grossa e Note di Viaggio in 

 America, Asia, Africa, Eiiropa. By Count Felice 

 Scheibler. Pp. xv + 525. Illustrated. (Milan : 

 U. Hoepli, 1900.) 

 T^ NGLISHMEN are, perhaps, somewhat too inclined 

 -L-" to believe that great game shooting is a special 

 prerogative of the Anglo-Saxon ; but the publication of 

 the present work, together with the recently issued 

 English translation of Count Potocki's " Sport in Somali- 

 NO. 1603. vol.. 62] 



land," should do something to dissipate this mistaken 

 notion. Count Felice Scheibler may, indeed, be said to 

 be a "mighty hunter," and the frequent mention of his 

 name in Mr. Rowland Ward's "Records of Big Game" 

 will suffice to show that many of the animals that fell to 

 his rifle have yielded trophies of more than usual size. 

 As is indicated in the title of the volume before us, the 

 author's seven years' hunting included experiences of the 

 great game of all the four continents of the world 

 although in .Asia his travels were limited to India and 

 Ceylon, and in America to the United States and the 

 Dominion of Canada. A well written and well illustrated 

 record of such extensive experiences could not fail to be 

 of interest, not only to his brother sportsmen, but like- 

 wise to naturalists ; and the present volume may be 

 truthfully said to fulfil both these conditions. The 250 

 text-figures with which the work is embellished are for 

 the most part reproductions from photographs taken 

 respectively by the author, Prince di Teano, and Mr. 

 Seton Karr, and are remarkable alike foi the manner in 

 which they have been executed and the care with which 

 they have been printed. A large number of these 

 illustrations deal with animals which were shot by the 

 Count, and although most of these were taken after 

 death, yet they frequently portray very clearly some of 

 the more striking characteristics of the particular species. 

 The views of scenery and hunting scenes are, moreover, 

 specially good, and will give to stay-at-home readers an 

 excellent idea of the nature of the districts in which 

 sport was obtained, and of the mode in which various 

 animals are hunted. Of especial interest is the photo- 

 graph, on p. 176, of recently captured elephants crowded 

 into a kedda, while those representing the elephant 

 tamers at work are scarcely less attractive. Some of the 

 titles to the illustrations, such as " II bufalo record," are 

 perhaps a little comic, but Italian, like French, has not 

 yet evolved a sporting language of its own. 



Although the author does not appear to have had the 

 good fortune to discover any new species, his accounts 

 of the habits of many of the less known forms will be 

 found of considerable interest to the naturalist. And a. 

 gratifying feature is the attention paid to nomenclature, 

 since this is a point in which sporting works are apt to- 

 be very deficient. In the employment of names like 

 Mazama Columbiana for the Columbian black-tailed deer, 

 and Taurotragus oryx for the eland, the Count is,, 

 indeed, thoroughly up-to-date and ahead of most works 

 on popular natural history. 



Whether, however, the author confined his love for 

 shooting within such limits as would meet with the ap- 

 proval of the recent congress on the preservation of great 

 game is a question which may be left for others to- 

 answer. But the plate on p. 457, which represents three 

 individuals of the common -African rhinoceros, out of a 

 herd of six, already fallen, while aim is being taken by the 

 author at a fourth, is calculated to give rise to misgivings 

 on this point. 



Startmg from Liverpool in 1889, Count Scheibler sailed 

 for America, where he soon enjoyed excellent sport in 

 the Rocky Mountains with "grizzly ' and wapiti ; after- 

 wards proceeding to British Columbia, where he was 

 successful in obtaining examples of the Rocky Mountain 

 goat. At San Francisco he embarked for India, where. 



