422 



SCIENCE 



[N. S. Vol. XXIX. No. 741 



by which the warmer waters from the north 

 replace the colder upper stratum, which moves 

 from the south. The temperatures naturally 

 have a very narrow range, comprised within 

 ten degrees of the point (28° F.) where sea 

 water freezes. 



The report on the pendulum observations is 

 preceded by a short and pathetic accoimt of 

 the life and services of Lieutenant E. Danco, 

 who died on the Belgica, at the age of twenty- 

 nine years and to whom these observations had 

 been confided. A fine portrait of Danco ac- 

 companies the notice. The work was carried 

 on subsequently by Lecointe, but owing to a 

 variety of circumstances the value of gravity 

 was obtained by the expedition only at Punta 

 Arenas in the Straits of Magellan. 



In his discussion of the glaciers and bergs 

 Arctowski considers first those of Tierra del 

 !Fuego, and secondly those of Gerlache Bay 

 and the Antarctic lands. He concludes that 

 the mountainous region of both was once con- 

 tinuous, the geology indicating much the same 

 characteristics. He also contrasts the effect 

 of the ice cap where incomplete and broken 

 by nunataks, and when existing as a continu- 

 ous covering extending to the sea level. In 

 the latter case and for Antarctica generally 

 he is disposed to believe that the ice is exer- 

 cising a comparatively small abrasive func- 

 tion, and that its effect on the subjacent rock 

 is very slight at present, the glacial streams 

 being clear instead of milky and rock forms 

 exposed by the retreating ice rounded oS 

 rather than channeled or excavated. This 

 memoir is illustrated by numerous excellent 

 haK-tone plates derived from photographs. 



The report on the barnacles considers a few 

 Magellanic forms and one new truly Antarctic 

 species, Verruca mitra, obtained in some 250 

 fathoms in south latitude 70°. Only one 

 strictly Antarctic species was previously 

 known, the Scalpellum antarcticum Hoek, ob- 

 tained by the Challenger. 



Only one species of Pennatulid88 was ob- 

 tained on the expedition. This belongs to the 

 genus Vmbellula first described from the Polar 

 Sea by Ellis from a dry specimen obtained in 

 1753. The Belgica species is U. carpenteri 

 KoUiker, first obtained by the Challenger. 



Two other species are known from the Ant- 

 arctic, of which one is so close to the Arctic 

 U. encrinus of Linne as to be regarded by 

 Kolliker as the same species. 



Only two scaphopods were recognized by 

 Plate in the collection, from south of latitude 

 70° S. One is referred to the Dentalium 

 majorinum, of MabiUe and Eochebrune, va- 

 riety gavssiariMm, previously described from 

 material obtained by the Gauss expedition. 

 The other, though probably a distinct species, 

 was not sufficiently perfect for description. 



The turbellarians comprised a new genus 

 and species of Acoela, Bimicola glacialis 

 Bohmig, and three species of Tricladidsi, of 

 which one, Procerodes hallezi, is described as 

 new. The latter is Puegian, having been 

 dredged in Beagle Channel. A new genus 

 and subfamily are described to include Pro- 

 cerodes (now Stummeria) marginata Haller, 

 The forms discussed are anatomically de- 

 scribed and figured in great detail. 



Wm. H. Dall 



A Text-hooh of Mechanical Drawing and Ele- 

 mentary Machine Design. By John S. 

 Eeid, Professor of Mechanical Drawing 

 and Designing, Armour Institute, and 

 David Eeid, formerly Instructor in Mechan- 

 ical Drawing and Designing, Sibley College, 

 Cornell University. Eevised edition, en- 

 larged. Pp. si 4- 433. New York, John 

 Wiley & Sons. 1908. 



It would be difficult, in fact practically im- 

 possible, to compress within equal limits more 

 of service to the student of machine design 

 who wished at the same time to qualify as a 

 draftsman. Not only are all necessary pro- 

 portions and tables given for the designing of 

 screws, nuts, bolts, keys, cotters and gibs, 

 riveted joints, shafting, pipes and couplings, 

 bearings, belt and toothed gearing, valves and 

 general engine details, but there are also full 

 data for drafting courses, with the unusual 

 feature of time-allotment included, securing 

 the early attainment by the novice of a com- 

 mercial rate of speed in his work. 



As indicative of the methods and procedure 

 in one of the leading technical schools the 

 book is of especial interest to teachers of 



