148 ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. . 
267. Total Weight of Iron.—The total weight of the arma- 
ture stampings is equal toi.icks Dee wes 4,870 lbs.; 
a value below that indicated in Fig. 14. 
The weight of the pole stampings amounts to ° 
12 X (6X 9 X 64+ 1.25 x 9 X 8.75) .X 0.28 = 1,450 Ibs. ; 
and that of the cast iron wheel rim to 
40.1 - 33.) 3.14 X 15.5 X 0.28 = 1,750 Ibs. 
Total amount of iron, 8,070 lbs. 
268. Summary of Results Obtained.—It should be of 
interest to know that the results of the actual tests on 
the machine under discussion agree with the calculated 
results. As close regulation was not specified, so more 
armature turns and less field ampere turns have been 
employed than is usual in a standard design. 
The copper is used economically, but it was impossible 
to dimension the armature iron in the most advantageous 
way, as the free choice of the designer was affected by the 
condition that he had to employ existing armature 
stampings with a somewhat excessive height above the 
slots. The tendency was to save material and a slightly 
smaller iron length has been applied, so that the tooth 
density with the same iron losses became slightly higher. 
In order to approach a standard design, the alternator 
should have less armature ampere turns, but more field 
ampere turns, which could have been effected by a slight 
increase of the air gap. Further, the armature would be 
longer and the core height smaller. 
DESIGN OF A LOW SPEED, REVOLVING FIELD 
TYPE, TWO PHASE ALTERNATOR. | 
269. General Specification of Alternator.—The dimen- 
sions of the flywheel type generator under discussion are 
