Reviews—Prof. Zirkel’s Petrography. 565 
which is not the original, but a substitute, in nearly every copy 
extant. 
Many of the fossils are re-figured and partially described by the 
Marquis de Gregorio '—those from the Middle Hocene of Claiborne, 
Alabama—but the drawings are not well done. In the two works 
under review we have fac-simile illustrations, whilst the text is a 
“Chinese copy” of Conrad’s own. The only additions are the 
editors’ introductory remarks and a useful index of genera and 
species to each volume. 
II].—Reuport on tHe Benpico Goup-Fietp. By EH. J. Dunn, F.G.S. 
Folio, pp. 20, with numerous Plans and Sections. (Melbourne, 
HIS is one of the “Special Reports” of the Department of 
Mines, Victoria. The object kept in view in this elaborate 
and well illustrated Report, by the painstaking Surveyor, is to 
indicate the direction and the extent, both longitudinal and trans- 
verse, of the known “reefs,” or lines of outcrop and underground 
foldings, of the gold-bearing rocks, so that the miners might carry 
on their operations not empirically, but with a real knowledge of 
the relative position of these rocks, whether seen or not at the 
surface, or in the existing mines and borings. ‘Thus the miner 
may often make sure of working progressively for a considerable 
distance ahead of his present shaft aud adits, along the axial lines of 
the anticlines and synclines, now here indicated by clear plans and 
sections, as well as where and how to follow the slopes (‘lines of 
pitch”) of the bent or folded strata with advantage. 
The special rocks of these saddles and troughs being known, they 
can be recognized in the “cross-cuts,” and “it will be possible to 
locate the precise zones of rocks through which work is contem- 
plated over the whole field.” 
Had such practical geological knowledge as is here placed at the 
command of the miners been appreciated and possessed by them, 
in Australia and elsewhere, in time past, it would have saved 
enormous waste of time, labour, and lives. 
IV.—Lenreucn per Perrocrapni. Von Dr. Ferpinanp ZIRKEL 3 
Zweite ginzlich neu verfasste Auflage. Hrster Band. Leipzig 
(Wilhelm Engelmann), 1893. 
HE twenty-seven years, which have elapsed since the last edition 
of this important work was published, have been extremely 
prolific so far as writings on petrographical subjects are concerned. 
It is, therefore, not surprising to find that the present edition, which 
is to consist of three volumes, will largely exceed the last in size. 
If the second and third volumes are each equal to the one now 
. before us, then the new edition will contain three times as much 
matter as the old one. This increase in size is certainly not out , 
of proportion to the increase in our knowledge. 
1 Ann. de Géol. et Pal. (Palermo), 7° and 8 liv. (1890). 
