beneath the surface at numerous points. Price in paper, §0 65 ; postage, ?0 Ifi. 

 Price in cloth, gO 90 ; postage, §0 IS. 



KK. Repokt op Pkogkess ix thk Fayettk and Westmoreland Dis- 

 TiiiCT OP THE Bituminous Coal Fields op Western Pennsylvania — 

 187G. By J. J. Stevenson ; pp. 437, illustrated by 50 wood-cuts and 3 county 

 maps, colored. Part I. Eastern Allegheny County, and Fayette and West- 

 moreland Counties, west from Chestnut Kidge. Price, $1 40 ; postage, $0 20. 



KKK. Report op Progress in the Fayette and Westmoreland 

 District of the Bituminous Coal Fields of Western Penns3'lvania — 1877. 

 By J. J. Stevenson. Pp. 331. Part II. The Ligonier Valley. Illustrated 

 with 107 wood-cuts, 2 plates, and 2 county maps, colored. Price, %l 40; post- 

 age, §0 IG. 



L. 1875 — Special Report on the Coke Manufacture op the Yougk- 

 lOGHENY River Valley in Fayette and Westmoreland Counties, 

 with Geological Notes of the Coal and Iron Ore Beds, from Survey's, by Charles 

 A. Young; hy Franklin Piatt. To which are a^jpended: I. A Report on 

 Methods of Coking, by John Fulton. II. A Report on the use of Natural Gas 

 in the Iron INIanufacture, by John B. Pearse, Franklin Piatt, and Professor 

 Sadtler. Pp. 252. Price, 51 00 ; postage, ?0 12. 



M. PbEPORT of Progress in the Laboratory of the Survey at 

 IIarrisburg — 1874-5, by Andrew S. McCreath. 8 vo., pp. 105. Price in pa- 

 per, §0 50; postage, $0 05. Price in cloth, 50 75 ; postage, ^ 08. 



MM. Second Report of Progress in the Laboratory op the Sur- 

 vey at IIarrisburg, by Andrew S. McCreath — 1S7G-8, including I. Classifica- 

 tion of Coals, by Persifor Frazer, Jr. II. Firebrick Tests, by Franklin Piatt. 

 III. Notes on Dolomitio Limestones, by J. P. Leslej-. IV. Utilization of An- 

 thracite Slack, by Franklin Piatt. V. Determination of Carbon in Iron or 

 Steel, by A. S. McCreath. With 3 indexes, plate, and 4 page plates. Pp. 438. 

 Price in cloth, gO C5 ; postage, ?0 18. 



N. Report of Progress — 1875-G-7. Two hundred Tables of Elevation 

 above tide level of the Railroad Stations, Summits and Tunnels ; Canal Locks 

 and Dams, River Riffles, etc., in and around Pennsylvania ; with riiap ; pp. 279. 

 By Charles Allen. Price, |0 70 ; postage, $0 15. 



O. Catalogue of the Geological Musuem — 1874-5-6-7. By Charles E. 

 Hall. Part I. Collection of Rock Specknens. Nos. 1 to 4,264. Pp.217. Price, 

 10 40 ; postage, ?0 10. 



P. 1879 — Atlas of the Coal Flora of Pennsylvania and of the 

 Carboniferous Formation throughout the United States. 87 plates 

 with explanations. By Leo Lesquereux. Price, f 3 35; postage, |0 22. 



Q. Report of Progress in the Beaver River District op the Bitu- 

 minous Coal Fields of Western Pennsylvania. By I. C.White; pp. 

 337, illustrated with 3 Geological maps of parts of Beaver, Butler, and Alle- 

 gheny Counties, and 21 plates of vertical sections — 1875. Price, ?1 40 ; jjost- 

 age, 50 20. 



QQ. Report of Progress in 1877. The Geology of Lawrence County, 

 to Avhich is appended a Special Report on the Correlation of the Coal 

 Measures in Western Pennsylvania and Eastern Ohio. 8 vo., pp. 336, with 

 a colored Geological Map of the county, and 134 vertical sections. By I. C. 

 White. Price, §0 70 ; postage, CO 15. 



V. Report of Progress— 1878. Part I. The Northern Townships of But- 

 ler county. Part II. A special survey made in 1875, along the Beaver and 

 Shenango rivers, in Beaver, Lawrence and Mercer Counties. 8 vo., pp. 248, 

 with 4 m,ops, 1 profile section and 154 vertical sections. By II. Martyn 

 Chance. Price, ?0 70 ; postage, |0 15. 



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