STREMMA TOGRAPH. 97 



tion into testing machines in the track and show how much 

 they are stressed due to the wheel loads and spacing of any- 

 type of locomotives and cars moving over the rails at the differ- 

 ent speeds of service. 



It is to replace what is now mere conjecture by reliable in- 

 formation that further progress may be made in the interest of 

 greater safety and economy. [See Plate XL, Fig. i.] 



The picture on the screen shows the first form of the Strem- 

 matograph attached to the base of the rail between the figures 

 2 and 3 on the scale bar, and under the front driver of the 

 freight mogul engine, No. 596, of the New York Central & 

 Hudson River Railroad. It is on the East-bound, or track No. 

 i; 5^-inch 80-lb. section; outside rail on a 3-degree curve 

 and down grade of 10 feet per mile. The location is opposite 

 the southeast corner of the West Albany Paint Shop. The ties 

 are yellow pine 7 by 9 inches and 2 5 -inch centres ; gravel bal- 

 last ; the tracks being in good condition. A number of tests 

 of passenger trains were made under the same rail. The ex- 

 periments made on track No. 2 were directly opposite, the rail 

 being the inside one of the curve. The section was the 5 -inch 

 80-lb. model of 1883 ; the rails were rolled in 1890 and all 

 straightened on narrow supports in the mills ; were heavily 

 gagged and had a wavy surface. 



The rails on track No. i are much smoother, the supports in 

 the straigthening presses having been made wider apart. On 

 track No. i two experiments were made with locomotiv^e No. 

 596, one at a speed of two miles per hour and one at ten miles 

 per hour. The total weight of the locomotive was 96 tons ; the 

 engine 60 tons, with 15,500 lbs. on pony truck and 104,500 lbs. 

 on three pairs of drivers. The tender weighed 72,000 lbs. or 

 9,000 lbs. per axle. This type of locomotive is the standard 

 for freight service for the road. 



It had been recently through the shops for general repairs, 

 the tires of the drivers having been turned the same as when new. 



The tender wheels were new cast-iron chilled wheels 33 

 inches in diameter and unground. 



At a speed of two miles per hour the locomotive passed over 



Annals N. Y. Acad. Sci., XI, April 20, 1898—7. 



