104 



DLDLEY. 



Results within a few pounds should be expected between the 

 computed and observ^ed stresses on the brick piers. Close results 

 must be obtained to test the mechanical perfection attained in the 

 construction of the instruments. 



The tests mentioned in the paper and many others have all 

 been made upon locomotives and trains in regular service. 



Table No i. 



Giving the General Dimensions of the Different Rail Sec- 

 tions Mentioned in the Tests of the Paper. 



Weight of 



Section 

 per Yard. 



Height 

 of Sec- 

 tion in 

 Inches. 



^\ 

 5 



5^ 

 6 



Width in 

 Inches of 



Thick- 

 ness of 

 Web. 

 Inches. 



^loment 



of 

 Inertia. 

 Inches.* 



Neutral 



Axis 

 Above 

 Base. 

 Inches. 



Moment 

 of Resist- 

 ance. 

 Inches.3 



Moment 



of 

 Inertia 



Head. 



Base. 



Axis. 

 Inches.* 



65-lb. Old 



Model. 



80-lb. Dudley, 



1883. 

 80-lb. Dudley, 



1890. 

 loo-lb. Dud- 

 ley, 1890. 



2| 

 3. CO 



4i 



4t6 



5 



5^ 



\ 



1 



il 



1 9 

 32 



16.60 

 26.00 

 28.50 

 48.50 



2.20 

 2.47 

 2.50 



2-93 



7-546 

 10.526 

 11.400 



16.553 



4.90 

 9.60 



Note. — In answer to a number of inquiries since reading my paper, regarding the 

 stresses in rails under static loads, I have added as an appendix, a portion of Mr. 

 James E. Howard's description and three tables from his experiments for *' Static 

 loads," set forth in extensio in the United States Government Report on Tests of 

 Metals and Other Materials for 1895. 



This will be a convenience to many who have not access to the above valuable 

 paper. 



APPENDIX. 



Railroad Track Experiments by Mr. James E. Howard. 



From Report of the Tests of Metals and other Materials for In- 

 dustrial Purposes, Made with the U. S. Testing Machine 

 at Watertown Arsenal, Massachusetts. For 18 g^. 



These experiments comprise observations on the fibre stresses 

 developed in rails in the track, the depression of the rails, and 

 the slope or inclination of the rails caused by the weight of the 

 different wheels of the locomotive. 



