Vi. W. H. WARREN. 
The ratio of high pressure to low pressure cylinder area is as 
1 is to 2:2, whereas in the continuous expansion engine with 
four cylinders of the Vauclain type, and in many of the French 
_ engines, the ratio is as 1 is to 3. Some locomotive engineers still 
consider that the economy saved in fuel does not more than com- 
pensate for the additional complication and higher boiler pressure. 
In regard to permanent way, the standard practice now consists 
of eighty feet lengths of rail with long angle fish plates at joints, 
and six bolts. Some of the rails weigh 100 ibs. per lineal yard on 
this railway. The formation is carefully graded and drained, and 
 _ is six inches higher in the centre than at the sides, there is from 
twelve to eighteen inches of ballast under the sleepers, the bottom 
ballast consisting of broken stone of larger size than in the top 
ballast. The high speeds attained on this railway and the freedom 
from shocks and vibrations is due to the high character of the 
road, and the excellence of the locomotives and cars. The ~ 
chemical composition of the steel used for the rails is for the 80 bs. 
rail as follows :— 
Carbon... oe from 55 to °6 
Silicon ... ae from ‘15 to °25 
Manganese ... from ‘8to 1 
Sulphur not to exceed i.) Oe 
Phosphorus not to exceed ... ‘060 
The lighter weights have less, and the heavier weights more carbon 
than given in the above figures. 
The drop test consists of a weight of 2,000 ibs. falling twenty 
feet and striking the rail which is supported on bearings three 
feet apart. Should fracture occur the portion in tension must 
_ show a minimum elongation of 5% or the lot of rails will be rejected. 
The American engineers prefer axles both for engines and cars 
made of Lowmoor iron in preference to steel, but in this matter 
they differ from English and European engineers, and I think 
their practice is in error. They use chilled cast iron wheels for 
cars, and pay special attention to the material used and mode of 
maintncttite, 
