35^J NEW nooKs. 



ground, the handling and transport of material, stoping and sand-liUing 

 operations, niine-ventilatior and the prevention of dust, the erection of 

 sanatoria for miners, the housing of mine emplo)-es, the estahlishment 

 of Mines training schools, the supply of unskilled lahour, and the im- 

 provement of native compounds. 



South African Institution of Engineers. — Saturday, Feliruary 24th: 

 J\Tr. F. H. Davis, President, in the chair. — " The evolution of printing 

 and type-setting machines " : A. E. Blevins. The paper, which was pro- 

 fusely illustrated, began with a brief survey of the history of printing, 

 and then proceeded in two sections, the first of which dealt with printing 

 machines under the following sub-heads: hand presses, platen machines, 

 cylinder or sheet printing machines, and rotary or web machines. The 

 second part of the paper consisted of a description of the progress efifected 

 by means of type-setting machiner\'. 



Royal Society of South Africa. — Wednesdav, ]^.Iarch 20: Mr. S. S. 

 Hough, E.R.S., President, in the chair. — " Bushman sticks decorated ov. 

 intaglio and poker work ; a note on the decorative skill of the P)ush 

 people and other aborigines " : Dr. L. Peringuey. The poker work was 

 probably of Kanr origin, whence the Bushmen may have obtained and 

 iinproved on it. The Bushman combined the two arts of painting and 

 graving, and were cripal)le of executing complicated nictographs — " Some 

 meteorological conditions controlling nocturnal radiation " : Dr. J. R. 

 Sutton. The lesults of hourly observations of radiation temperature 

 between sunset and midnight by means of spirit tliermometers. After 

 allowing for the state of the sky and the movement of the air, the onlv 

 iu/portant factor determining rad!;ition temperature gradient is relative 

 humidity. — " Tlie resultant of a set of homogeneous lineo-linear equa- 

 tions."' : Dr. T. Muir. Three methods were given for obtaining the re- 

 sultant, to (ine of which Sylvester referred in 1863, without, however, 

 publishing what he asserted to have been the successful outcome of his 

 researches. — " Tlie variation in the value of the atmospheric electrical 

 potential with the altitude " : Prof. W. A. D. Rudge. An account of 

 observations taken in different parts nf South Africa to find the relation 

 between atmospheric potential gradient and altitude. The potential 

 gradient was found to vary greatly with altitude, the extreme value at 

 6.500 feet altitude being only one eighth that at sea level, and generally 

 the greater the altitude the smaller the potential gradient. Johannesburg 

 proved an exception to this, owing to the clouds of steam, and cspeciallv 

 Oi the dust proceeding from the mine heaps. — " Respiration and cell 

 energy": Prof. H. A. Wager. The tlieory that the energy required in 

 all organic life is derived either directly or indirectly from the sun is 

 disproved. Energy cannot be stored away to be drawn on when required. 

 The first energy available in a cell prol)ably comes from synthetic pro- 

 cesses set up l^y the introduction of water or oxygen into the cell, and the 

 energy set free during the union of oxygen with liberated carbon is 

 probably the main source of all energy manifest in organic life. 



NEW BOOKS. 



Thomsen, Dr H. — Dnitschcs Land in Afrika. ^Munich : Verlag d. 



Deutschen Alpenzeitung. 1911. 10] X 7\- PP- viii, 188. ^lap-^ and 



illus. i6s. 

 Letcher, Owen. — Big, iianic hnntinti iv Xortli-Eastern Rliodcsic. 



London: J. Long. Ltd., 1911. 9 X SJ pp. 266. Maps and illus. 



i2s. 6d. 

 Playne, Somerset. — Cahc Colony (Cape Province^ : its hisiory, coii^- 



inrrce. industries, and resources. London : Foreign and Colonial 



Publishing Co., 1910-11. 12 J- X 9-}. pp. 792. ^Maps ;>.nd illus. 



25s. 

 Hodson, Arnold MI.—Trekkin'^ the G'-eat Thirst: traz'cl and sport in 



the Kiilaltaii Desert. London: T. Fisher Unwin. 1912. 9X6. 



pp. 360. Maps and illus. 12s. 6d. 



