36 



SCIENCE. 



Vol. XIV. No. 337 



A great deal of attention has been paid in the design of this 

 motor, while great care has been taken in regard to durability and 

 strength, to reducing the weight to a minimum. For this pur- 

 pose, and with this object in view, cast iron has been dispensed 



GIRDLING TREES TO IMPROVE FRUITFULNESS. 



In many sections where the soil is moist and rich, fruit-trees' 

 grow largely to wood and foliage, and fail to produce fruit until 

 they reach considerable age and size. To discover som^ means of 



FIG. a. — NEW SPRAGUE ELECTRIC-RAIl.WAY MOTOR. 



with in the cores and yoke of the field-magnets, and wrought iron 

 substituted. 



These motors are already in operation at Wichita (Kan.), Marl- 

 borough (Mass.). Cleveland (O.), Cincinnati (O.), Erie (Penn.), At- 



hasteningthe fruiting of such trees, the following experiments were 

 made at the Hatch Experiment Station of the Massachusetts Agri- 

 cultural College. A row of crabapple-trees of about the same size 

 and condition of growth were selected, and treated as follows: ist. 



FIG. 3. — NEW SPRAGUE ELECTRIC-RAILWAY MOTOR. 



lantic City (N.J.), and at one or two other places where they have 

 been installed. Theyhave been shown to give very good results, 

 and in the future this'type of motor will be used in all of the 

 Sprague electric-railway installations. 



Three trees were girdled by cutting out a ring of bark J-, -J, and J 

 inch wide at the ground, July 12, 21, and 29 ; 2d, Three trees were 

 girdled just below the main branches with the three widths of 

 girdle as in 1st. July 12, 2r, and 29; 3d, The same as above was 



