1898-99.] Admiral Makaroff on Oceanographic Problems. 403 
and on my return from the Pacific Station, I was happy to learn 
that he and his “Fram” had safely returned home. Of course, 
that deprived me of my pretext for collecting the necessary money 
for building a large ice-breaker, hut I found another motive — 
this time purely commercial. 
You know that the Gulf of Finland of the Baltic Sea is covered 
with ice during the whole winter, and that the navigation and 
transport of cargo to such an important commercial port as St 
Petersburg is interrupted for five months in the year. In a severe 
winter ice may he found at a distance of 200 miles from St 
Petersburg. The ice of the Finnish Gulf is very strong because 
the water of the Baltic has very little salt in it. The thickness of 
plain ice does not exceed two feet in deep places, and three feet 
in shallow water, hut the winds break the ice and pile it up, and 
large fields of packed ice 12 feet deep may often he found. An 
ice-breaker ought to be strong enough to go through ice of this 
description. 
The first ice-breaker was built by a Russian merchant, Britneff, 
who took one of his steam tugs and cut the fore part into such a 
shape that it would run on the top of the ice and break it with its 
own weight. The trial took place in 1864 and proved very 
successful, and then the authorities of the city of Hamburg and 
some important ports of the Baltic constructed ice-breakers for 
themselves on the same principle, which prevails up to this day. 
A great improvement in ice-breakers was made in America by 
introducing a fore propeller. I am sorry to say that I do not 
know the name of the inventor of the fore propeller, but it adds 
considerably to the efficiency of the ice-breaker. The fore propeller 
sucks the water from under the ice, and washes the skin of the 
ice-breaker, delivering it from the pieces of ice which otherwise 
would stop the progress of the ship. Anyhow, if it happens that 
the ice “ torros ” is very powerful and stops the ice-breaker, then 
the fore propeller is reversed, and the water pushes forward the 
pieces of ice that compose that “torros.” Plate X. shows how 
this is done. One minute of such working of the propeller is 
usually enough to shake the “ torros ” ; after this the engine is again 
reversed to speed ahead (stern engine always working ahead), and 
then the ship proceeds. The ice-breakers in America are used on 
