Popular Science Moiithh/ 



539 



BOILER HOUSE-' .t 

 SUPPLIES STEAM ft 

 FOR ROCK DRILLS 



There will be 

 nothing left to 

 injure the bottom 

 plates of vessels. 

 In the oval : The 

 river is shown re- 

 entering the exca- 

 vation after com- 

 pletion of work 



the Black Rock Dam, near Buffalo, it 

 was necessary to ha\e three fifteen-inch 

 wrecking pumps in continual operation. 

 To-day the drained area on the east 

 side of the Hudson is noisy with an 

 incessant chorus of drills, with the oc- 

 casional counterpoint of a heavy blast. 

 When the carving of the slips or water- 

 ways is completed, there will be no ob- 

 structions to injure the bottom plates of 



vessels floating there. The piers will 

 be one thousand and fifty feet in length, 

 and one hundred and fifty feet in width. 

 One interesting feature about the 

 piers is that only a small part of their 

 length will be supported by actual con- 

 tact with the underlying rock. The re- 

 mainder will float, and the anchorage 

 will be the grip which the piles have on 

 the semi-fluid mud of tl^e river bottom. 



