508 



SCIUJ^CU. 



[Vol. VIII., No. 200 



away to show the interior. In the bow are two 

 cylindrical water-tanks, above which are two 

 steering-levers, within easy reaching distance of 

 the captain. There is also a small steam-pump 

 for filling or emptying the tanks. The captain 

 stands with his eyes on a level with the glazed 

 apertures in the conning-dome, whence he has a 

 view all around the horizon while above the 

 surface. When submerged, he shapes his course 

 by a compass. Near the middle of the boat is the 

 steam-boiler, abaft of which is the engine. In the 

 stern are three cylindrical water-tanks similar to 

 those in the bow, and for the same purpose. A 

 large steam-pump stands just forward of the tanks. 

 Several compressed-air pipes, each six inches in 

 diameter, extend along the sides of the boat, near 

 the bottom. 



When the boat was first built, electricity was 

 tried as a motive power. The storage-batteries 

 and electric motor, being found inadequate, were 



into the solution, by which it is absorbed, the pro- 

 cess developing heat, which produces more steam 

 in the boiler. This is continued until the solution 

 will absorb no more steam, when the surplus 

 moisture must be driven off before the operation 

 can be repeated. 



At a recent trial of the boat, a representative of 

 Science was permitted to witness the operation of 

 charging the boiler, and to become a passenger in 

 the boat during her submarine voyage. Water, 

 heated under pressure to above the boiling-point, 

 was pumped from a boiler on the deck of the tor- 

 pedo-boat's tender to the inner compartment of 

 the boat's boiler, and the outer compartment was 

 filled with the soda solution previously heated to 

 about 260° F. in a tank on the tender. The cap- 

 tain and engineer, accompanied by the Science 

 reporter, descended into the boat through the 

 manhole, which was then securely fastened on the 

 inside. The captain took his place at the steer- 



THE PEACEMAKER. 



removed, and a Honigmann fireless boiler and a 

 fourteen-horse-power steam-engine substituted. 

 With these it is claimed that eight knots an hour 

 for several hours may be maintained with one 

 charge of caustic soda. The speed and steam- 

 endurance depend, of course, upon the capacity 

 of the boiler and the efficiency of the machinery. 

 The propulsion of the boat by steam power for 

 any great length of time while submerged would 

 not have been possible before Honigmann's inven- 

 tion, a few years ago, of the fireless boiler which 

 bears his name. This invention is based upon the 

 discovery that a solution of caustic soda liberates 

 heat while absorbing steam, which heat may be 

 utilized for the production of fresh steam. The 

 Honigmann boiler, as used on the Peacemaker, is 

 double, the innerpart containing water and steam, 

 and the outer surrounding vessel containing a 

 saturated solution of caustic soda heated to within 

 a few degrees of the boiling-point. The steam, 

 after doing its work in the engine, is exhausted 



ing-levers, with his head in the dome, the engi- 

 neer and reporter stationing themselves at the 

 engine. Light was furnished by two- candle- 

 power electric lamps. The steam-gauge showed 

 eighty pounds pressure. All being in readiness, 

 water was admitted to the ballast-tanks until the 

 dead-lights in the dome — which had up to this 

 time been about a foot above water — were almost 

 even with the surface. The order was then given 

 to go ahead, the engine was started, and the 

 boat shot ahead, showing only her 'fin' above 

 water. The captain guided her movements with 

 ease, describing curves, going straight ahead, or 

 forcing her below the surface, untU the pressure- 

 gauge which communicated with the water on 

 the outside showed a depth of forty feet. The 

 steam-gauge showed a steady increase. in pressure, 

 from 80 pounds at the start, to 120 when the boat 

 ran alongside the tender a half-hour later. The 

 back-pressure gauge, which was connected with 

 the soda-solution compartment of the boiler, 



