AN APPRAISAL OF POWER USED ON FARMS 
47 
ADVANTAGES — Continued 
DISADVANTAGES — Continued 
Gas tractor: 
Can work continuously at heavj^ 
loads. 
Not affected by hot weather. 
Adapted both for stationary and 
for most draft work. 
Great range of working speeds. 
No attention required when not in 
use. 
Requires no feed or fuel when not 
in use. (Applies to all me- 
chanical power.) 
Quickly available when needed in 
an emergency. » 
Stationary gas engines: 
Has practically the same advan- 
tages and disadvantages as the 
gas tractor as applied to sta- 
tionary work. Its special ad- 
vantage over the electric motor 
is its greater portability. 
Steam engines: 
Great overload capacity. 
Smoothness and flexibility of oper- 
ation. 
Adapted for both draft and sta- 
tionary work. 
Uses fairly cheap fuel. 
Usually a cheap type of power 
when used in large units. 
Windmill : 
Cheapness when used direct. 
Requires little attention when in 
use. 
Requires no attention when not in 
use. 
Electric motor: 
Extreme convenience in operation. 
Requires little attention when in 
use. 
Requires practically no attention 
when not in use. 
Considerable overload capacity. 
Adapted to practically all kinds of 
belt work. 
Especially adapted to direct-cou- 
pled power installations. 
Electricity may be used for heat- 
ing and lighting as well as 
power. 
Water power: 
Operating cost very low as a rule. 
Convenient type of power for gen- 
erating electricity and for all 
direct power when suitably lo- 
cated. 
Gas tractor: 
Limited overload capacity. 
Poor traction in wet or loose 
ground. 
Not adapted to all kinds of draft 
and field work as now con- 
structed and requires other 
kinds of power to supplement 
it under some conditions. (Same 
applies to all forms of mechani- 
cal power.) 
Requires mechanical skill for suc- 
cessful operation. 
Inflexibility of size of power unit 
for economical power produc- 
tion under some conditions. 
(Same applies to all forms of 
mechanical power.) 
Stationary gas engines: 
Its disadvantages over the electric 
motor are: Less convenience in 
starting, greater noise in opera- 
tion, and greater amount of care 
required in keeping it in adjust- 
ment. 
Steam engines: 
Requires constant attention while 
in use. 
Usually requires extra attendant 
to provide fuel and water. 
Fuel and water bulky and incon- 
venient. 
Loss of time while getting up 
steam. 
Requires special mechanical skill 
for successful operation. 
Windmill : 
Undependability when used direct. 
Variations in wind velocity. 
Expensive when energy is stored. 
Use limited to stationary work 
when used directly. 
Electric motor: 
Electricity expensive to distribute 
from central plants under low- 
load factors. 
Expensive to store energy from 
isolated plants. 
Isolated plants not efficient unless 
operated at near full load. 
Difficult to apply direct to draft 
or field work. 
Expensive if applied indirectly to 
draft work. 
Water power: 
Use limited to local stationary 
work when used direct. 
Installation costs usually high 
when used under low heads, re- 
sulting in high fixed charges. 
