382 . Notices respecting New Books* 



steadily throughout the spectrum, the transparency for the 

 region beyond the G line being only three fourths as great as 

 that for red light. 



In the case of the Nicol's prisms, however, the transparency 

 throughout the red and yellow is quite uniform, diminishing 

 less than one per cent, between the A line and the D line. 



In the blue and violet, on the other hand, absorption 

 appears to be relatively more marked in calcite than in glass. 



Physical Laboratory of Cornell University, 

 Ithaca, New York, June 1, 1891. 



XLIII. Notices respecting Neiv Books. 



Guide through the Collection of Building-materials in the Imperial 

 Natural-history Museum at Vienna. [Fiihrer durch die Bauma- 

 terial-Sammlung, &c] By Felix Kaeeee. Small 8vo. 355 

 pages, with numerous plates. Lechner ; Vienna. 



YXR. AEISTIDES BKEZINA, Director of the Mineralogical 

 -*-* Department of the Museum, gives a short Preface, noticing 

 the history of this special collection, giving due credit to those who 

 have helped in the work, and especially acknowledging the industry 

 ana acumen of P. .Kaeeee in perfecting this extensive and useful 

 Collection. An Introduction gives (1st) a general account of the 

 collection and of the method followed in its arrangement and in the 

 Guide-book : (2nd) brief notices of the characteristics of the most 

 common and useful rock-materials : (3rd) the geological order of 

 the rocks and strata : (4th) a Bibliography of memoirs and books 

 on constructive materials, in chronological order from 1831. 



In the body of the work the main arrangement is geographical ; 

 and a city or town in each division, in many cases supplying one 

 or more chief buildings (of which there are forty ' ; phototypes''), 

 has a detailed account of the nature and sources of the various 

 building-materials used in these constructions ; and its paving- 

 stones and road-metal are also carefully noted. Thus Vienna, 

 Linz, Salzburg, Innsbruck, Bregenz, G-raz, Klagenfurt, Laibach, 

 Gorz, Truest, Parenzo, Zara, Prague, Briinn, Troppau, Lemberg, 

 Cracow, Czernowitz, Budapest, Hermann stadt, Klausenberg, and 

 Agram, give full opportunities for detailing the particulars of the 

 building-stones, decorative stones, sand, lime, hydraulic cement, 

 plaster, bricks, roofing-stone, &c, locally used in Austria-Hungary. 

 Of foreign countries large and well-known buildings at Cologne, 

 Begensburg, Strassburg, Niirnberg, Dresden, Borne, Milan, Paris, 

 Brussels, and Schaerbeck are illustrated; and the materials used in 

 them and in other buildings, as well as in streets and roads, are 

 enumerated according to the many examples in the Museum. 

 Shorter, but useful, notices of the building-materials in the Museum 

 from England, Norway, Bussia, Switzerland, Spain, Portugal, 



