D. VAN NOSTRANU. 31 



Rogers Geology of Pennsylvania. 



3 Vols. 4to, with Portfolio of Maps. Cloth. $30.00. 



THE GEOLOGY OF PENNSYLVANIA. A Government Sur 

 vey. With a general view of the Geology of the United States, 

 Essays on the Coal Formation and its Fossils, and a description 

 of the Coal Fields of North America and Great Britain. By 

 HENRY DAHWIN EOGERS, Late State Geologist of Pennsylvania. 

 Splendidly illustrated with Plates and Engravings in the Text. 



It certainly should be in every public library throughout the country, and 

 likewise in the possession of all students of Geology. After the final sale of 

 these copies, the work will, of course, become more valuable. 



The work for the last five years has been entirely out of the market, but a 

 few copies that remained in the hands of Prof. Rogers, in Scotland, at the 

 time of his death, are now offered to the public, at a price which is even, 

 below what it was originally sold for when first published. 



Morfit on Pure Fertilizers. 



With 28 Illustrative Plates. 8vo. Cloth. $20.00. 



A PRACTICAL TREATISE ON PURE FERTILIZERS, and 



the Chemical Conversion of Rock Guanos, Manlstones, Coprolites, 

 and the Crude Phosphates of Lime and Alumina Generally, into 

 various Valuable Products. By CAMPBELL MORFIT, M.D., F.C.S. 



Sweet s Report on Coal. 



8vo. Cloth. $3.00. 



SPECIAL REPORT ON COAL ; showing its Distribution, Classi 

 fication, and Cost delivered over different routes to various points 

 in the State of New York, and the principal cities on the Atlantic 

 Coast. By S. H. SWEET. With maps. 



Colbnrn s Gas Works of London. 



12mo. Boards. 60 cents. 

 GAS WORKS OF LONDON. By ZERAH COLBUKN. 



