GENfchA.. 



aiiUMINOFERRIC 





1 LIBRyVRY , ■ • 



OF THE 



University of California. 



Class 



ilES. 



'in. 





Samples, quotation, 



and full particulais 



may be obtained 



from — 



PETER SPENCE & SONS, Ltd., 



Manchester Alum Works, MANCHESTER, England. 



NOW READY. 



Attrition Tests of 



f 



Road-Making 

 Stoftes, ^= 



— BV — 



E. J. LOVEGROVE, M.Inst.O.E., 



Borough Engineer and Surveyor of Homsey, 



— WITH - 



Petrological Descriptions, 



— BY — 



JOHN S. PLETT, M.A., D.Sc, P.R.S.E., 



Petrograpker HM. Geological Survey ; and 



J. ALLEN HOWE, B.Sc, 



Curator and Librarian of the Museum of Practical Geology. 



Price FIVE SHILLINGS Nett 



(Post Free). 

 K" 



Size, Demy 4to (9 in. by 11 in.). 



Printed on art paper and handsomely bound in 

 art vellum doth, lettered on back and side, jt 



Vith SEVENTY-NINE Illustrations and Diass-ams. 



««• 



CONTENTS. 



Introduction— Table of Attrition Tests— Petrological Descrip- 

 tions: Granite Group ; Porphyry and Porphyrite Group; Basalt 

 and Diabase Group ; Andesites ; Homfels ; Quartzites and Sand- 

 stones ; Umestones and Dolomites ; Flints j Discussion of the 

 Results— Valuation of the Numerical Results— General Con- 

 clusions—Description and Average Hardness of Minerals— 

 Glossary of Technical Terms— Index to Localities— Appendix 

 (Giving Results of Seventy-seven Additional Attrition Tests). 



London : 



The ST. BRIDE'S PRESS, I,imited, 



St. Bride's House, 34 Bride I,ane, 



Fleet Street, E.C. 



^ 



