G32 NEW YORK STATE MUSEUM 



wide and 7 to 9 feet high. Roads lead up to the separate benches, 

 and each bench is worked in advance of the lower o^ne. 



"Where the clay has streaks of quicksand the roads have to be 

 planked. If the bank is below water level there is the additional 

 expense of pumping. This method is of importance along the 

 Hudson river, where many of the clay banks are of considerable 

 hight, and the use of benches often prevents a slide of the clay. 



4 Steam sliovel. Though this method of mining has been suc- 

 cessfully practised at many western localities, the only place in this 

 state where it has been tried is Croton landing in the Hudson valley. 

 These clays do not as a rule stand well with a vertical face, and as a 

 result the bank slid, burying the shovel. Where the clay bank 

 contains several different layers of clay, which are mixed together 

 for making brick, the steam shovel is a good thing, as it digs from 

 bottom to top of the bank at each stroke. Steam shovels are an 

 economical means of mining soft shale, where the capacity of the 

 yard warrants it, and may also be used for clay. 



5 Dredging. This method like the preceding is only practised at 

 Haverstraw and Croton point. The dredged clay isi dropped into 

 hoppers, which, when full, are run up inclined planes on shora and 

 dumped. Cost 12-15c a thousand delivered on shore; then 12c 

 for haulage to ring pits. 



6 Undermining. Many brick manufacturers use this method of 

 mining their clay, specially when the latter is tough. Wedges are 

 driven in on the upper surface, a foot or two from, the edge; at the 

 same time the face is undermined by picking, to a distance of 2 

 or 3 feet. It is not advisable to work a bank more than 20 feet 

 high by this means, and in almost any case it is a rather dangerous 

 method to employ. 



Y Blasting is very often resorted to in banks of tough clay and 

 always in the case of a shale bank. A small charge of dynamite 

 usually suffices to bring down a large quantity of the material. 



8 Haulage. The brick manufacturer generally establishes his 

 plant near the supply of clay, so that the haulage distance is from 



