40 CONTEMPORARY SCIENCE 



opportune to say one word as to their further develop- 

 ment. The size of ships has been steadily increasing up 

 to the time of the war, resulting in a reduction of power 

 required to prtopel them per ton of displacement. On the 

 other hand, thanks to their greater size and more eco- 

 nomical machinery, speeds have been increased when the 

 traffic has justified the greater cost. The limiting factor 

 to further increase in size is the depth of water in the 

 harbors. With this restriction removed there is no ob- 

 stacle to building ships up to 1,000 feet in length or more, 

 provided the volume and character of the traffic are 

 such as to justify the capital outlay. 



Tungsten Steel. Among other important pre-war de- 

 velopments that have had a direct bearing upon the war, 

 mention should be made of the discovery and extensive 

 use of alloys of steel. The wonderful properties con- 

 ferred upon steel by the addition of tungsten were dis- 

 covered by Muschet 1 in 1868, and later this alloy was in- 

 vestigated and improved by Maunsel White and Taylor, 

 of Philadelphia. The latter showed that the addition of 

 tungsten to steel has the following effect: That after the 

 steel has been quenched at a very high temperature near 

 its melting point it can be raised to a much higher tem- 

 perature than is possible with ordinary carbon tool steel, 

 without losing its hardness and power of cutting metal. 

 In other words, it holds the carbon more tenaciously in 

 the hardened state, and hence tungsten steel tools, even 

 when red 'hot, can cut ordinary mild steel. It has revo- 

 lutionised the design of machine tools and has increased 

 the output on heavy munition work by 100 per cent., and 

 in ordinary engineering by 50 per cent. 



The alloys of steel and manganese with which the 

 name of Sir Robert Hadfield is associated have proved 

 of utility in immensely increasing the durability of rail- 

 way and tramway points and crossings, and for the hard 



iWho has not been sufficiently credited with his share in 

 making the Bessemer process a practical success. 



