188G.] NEW YORK ACADEMY OF SCIENCES. 151 



roads are gradually improving them. The Boston and Albany 

 have spent large sums of money on their track for a number of 

 years, and in the past two years have reduced their average de- 

 flection per rail over one-eighth of an inch. I have run my 

 " Dynagraph and Track Inspection Car'' over their tracks three 

 or four times a year to mark deflections, many of which would 

 escape the eye of the trackman. 



Their gross income in 18S3 was about 18,540,000. In 1884 it 

 fell short $392,000, and in 1885, $510,000 from the year before. 

 The improvement in their tracks has been so great, and the 

 operating expenses so reduced thereby that in these two years 

 their net income has only fallen $36,000 below that .of 1883. 



Of the improvements made in passenger travel, I hardly need 

 speak. The parlor, sleeping, and dining-cars give comfort and 

 luxury to travel. Chicago, 1,000 miles from New York, is only 

 twenty-five hours in time. One can sleep and eat on the same 

 train, and get a daily paper. The diflierence between all this and 

 the inception in 1830, shows the progress of our great railway 

 system of 1886. 



DISCUSSION". 



The President, .Prof. Trowbridge, Dr. Hubbard, Mr. 

 ]McDoNALD and others participated in the discussion. 



In reply to inquiries, Mr. Dudley made the following re- 

 marks. 



One cause of the breaking of ordinary iron or steel axles is due 

 to the more or less granulated or crystalline structure. A thin 

 lamina seems to join one granulation to another; the latter are 

 coarse or fine according to the quality of the metal and the method 

 of manufacture. When the axles are repeatedly and quickly 

 strained, even much below the elastic limits, the cohesion of the 

 laminee is lessened and they eventually separate along the planes 

 of the granulations. From examination of a number of broken 

 axles, the planes appear to increase in size, up to a certain ex- 

 tent, the longer the axle is used. One of eighteen months' ser- 

 vice has larger planes apparently than one of only twelve months' 

 use. Examination with the microscojte shows that more of the 

 lamina which are at right angles to the planes are broken, 

 and one or two and sometimes more jilanes are joined to form 

 one face. 



Stone ballast is not quite so elastic as good gravel, but it is 

 not so much affected by water, and is much freer from dust. 

 In England it is very extensively used. Every few years where 

 the traffic is heavy it must be reworked to remove the cinders 

 •ejected by the locomotives. 



