506 E. P. TAYLOR. 
8. Types of Engines tested.—This research was carried 
out on three engines belonging to the Mechanical Engineer- 
ing Laboratory plant. Most of the experiments were made 
on the smallest of the three—a 6-H.P. Victor Oil Hngine 
of 6" bore and 8” stroke. There were two flywheels, one 
on each side of the engine, and the rotary mass had a 
moment of inertia of 17°6 feet Ibs. units. 
The engine was of the vertical enclosed-crankease type 
with plain bush bearings lubricated by the splash in the 
crankcase running through holes in the upper part of the 
bearings. This crude method of oiling the bearings gave 
considerable trouble until it was decided to keep the bear- 
ings always flooded by hand feeding, giving a condition 
that could be repeated at any time. The necessary speed 
was attained by belt drive from an electric motor, the 
belt being simply run off the pulleys to commence a test. 
A record was kept of the temperatures of the main bearings 
and cylinder. This is an important point, for previous to 
this, tests made under apparently similar conditions often 
disagreed as to their results owing almost entirely to the 
temperature of the rubbing surfaces having altered. 
The second engine to be tested was a 40-H.P. National 
Gas Engine of the usual horizontal four-stroke cycle type, 
—hbore 11”, stroke 19”, and one large flywheel] supported 
between one of the main bearings and an outside pedestal 
bearing. The moment of inertia of the rotating masses 
was 1940 ft. Ibs. units. Directly coupled to the engine 
shaft by means of a leather-laced flexible coupling was a 
25 K.W. generator. 
The three engine main bearings and two generator bear- 
ings were normally well lubricated by ring lubricators; 
the piston and connecting rod by sight-feed drip lubricators. 
This metbod of oiling was found to give quite satisfactory 
service for the tests and so was retained unaltered. The 
