PREFACE. 



This Report is Vol. VI, in the Final Report series of the 

 Geological Survey, the previous volumes being as follows : Vol. 

 I, Topography (out of print) ; Vol. II, Pt. I, Mineralogy and 

 Botany (postage, 25 cents) ; Vol. II, Pt. II, Zoology (postage, 

 30 cents) ; Vol. Ill, Water Supply (postage, 21 cents) ; Vol. 

 IV, Physical Geography (very scarce), 1 and Vol. V, Glacial 

 Geology (postage, 35 cents). 



The value and importance of the New Jersey clays and clay 

 industry have long been known and much attention has been 

 given to them by the Geological Survey. In his report entitled 

 "The Geology of New Jersey," published in 1868, Prof. Cook 

 described the clays about Woodbridge and South Amboy, and 

 gave numerous chemical analyses! Ten years later the Survey 

 issued an elaborate report upon the Clay Deposits of Woodbridge, 

 South Amboy and other places in New Jersey. This volume was 

 accompanied by a map showing the location of all the clay pits 

 in the Woodbridge-Amboy district, and also' the geographical 

 distribution of the beds of fire clay, feldspar and potter's clay. 

 The information made public by this report and map was of 

 great importance. 



Prospecting for clays was stimulated and at the same time 

 large sums of money were saved to the clay miners by the in- 

 formation given as to the distribution of the clay and the regions 

 where success was to be sought. A striking commentary upon 

 the accuracy of this map is that all the new clay openings made 

 since 1878 are within the areas marked as clay, in so far as they 

 are within the area covered by the map. Considerable clay is 

 now dug from areas beyond the limits of the former map, but for 

 the area covered, it was accurate and reliable, as shown by sub- 

 sequent developments. 



1 For sale, prepaid, $1.35, without the accompanying photo relief, map; 

 $2.85 with map; map alone, $1.50. 



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