660 



HISTORY OF THE SEA. 



form this work, General Newton has had a special boat built, 

 a scow, a low-lying, box-like craft, with a confusion of timbers, 

 ropes, chains, and machinery surrounding a huge dome in the 

 center. This vessel is very solidly built, and anchored so firmly 

 that the waves strike against its sides as against a wharf. This 

 strength is important for the work, and also to protect the ma- 

 chinery against the chance collision of the constantly passing 

 vessels in the harbor. The general purpose of the scow is 

 easily comprehended. Its object is to guard the drilling ma 



READY TO GO DOWN. 



chinery while it is at work ; to transport it when necessary, and 

 to support the engines for working the drills. In the center 

 of the scow is an octagonal well, thirty-two feet in diameter, 

 in which is supported an iron- wrought dome for protecting the 

 divers. At the top of the dome is a "telescope," twelve feet 

 iii diameter, with a rise and fall of six feet to adapt it to the 

 various stages of the tides. When the dome is in working or- 



