12 British Antarctic Expedition. 
The low-pressure cylinder has a piston rod going 
straight through. The engine has а _ surface 
condenser, and is in other details furnished with all 
modern appli- 
ances ol a 
marine engine, 
with 100 revolu- 
tions a minute, 
and a pressure 
of 170 lbs. per 
square inelt, 
(H р 59. 
The propeller 
has two blades, 
ame: has 8 10 ft. 
diameter, with 
9.ft. 3 ine (grad- 
ual rise) (Nor- 
wegian Stign- 
ing). To this 
engine 15 at 
tached combin- 
ed furnace and 
boiler tubes of 
steel, to withstand a pressure of 170 lbs. to the square 
inch. The boiler is чі ft 3m m daner and 
9 ft. ro in. long. The two furnace waving plates 
are 3 ft. 3 in. in diameter. Each of the 158 pieces of 
horizontal tubes are 34 in. in diameter outside. The 
heating surface is 1,100 Sq. dt The orate arca 
43 Sq. ft. The engine as well as the boiler and the 
tubes were executed according to the rules of the 
Norwegian Veritas, 
C. E. BORCHGREVINK. 
