NORMAL DAYS WORK FOR VARIOUS FARM OPERATIONS. 
15 
In Table VI the original data for the most common widths of 
spike-tooth harrows are tabulated by horses in the team. Adjusted 
acreages have been computed for these widths and allowances indi- 
cated for other widths. From an inspection of this table the daily 
duty of any spike-tooth harrow unit and team can be readily ascer- 
tained, as well as the limit of feasible width for the respective teams. 
Table VI. — A normal day's work with a spike-tooth harrow, giving the average acreages 
reported for the widths most frequently used and adjustments for other ividths. 
[Net hours in the 
field, 9.65.1 
Width of harrow. 
On freshly plowed land. 
On well-packed land. 
Num- 
ber of 
horses. 
Range. 
Most 
common 
width. 
Har- 
rowed 
per 
day. 
Number 
averaged. 
Adjusted 
acreage. 
Allow- 
ance for 
each foot 
in width. 
Har- 
rowed 
per 
day. 
Number 
averaged. 
A How- 
Adjusted ance for 
acreage. . each foot 
in width. 
2 
3 
4 
Feet. 
4-12 
8-16 
10-26 
Feet. 
8 
10 
16 
Acres. 
10.8 
15.3 
28.3 
224 
149 
112 
9.50 
13.5 
25.0 
Acres. 
1.2 
1.5 
1.8 
Acres. 
12.9 
19.0 
35.1 
194 
140 
102 
11.5 
17.5 
32.0 
Acres. 
1.5 
1.8 
2.0 
Analysis of the data for spring-tooth harrows indicated that 49 
per cent of farmers use two horses, 33 per cent use three horses, and 
11 per cent use four horses. The 6-foot harrow is used by 38 per 
cent, or twice as many as use any other width, while about equal per- 
centages use 5, 7, and 8 foot widths, and very limited numbers use 
any other size. Since the widths used in spring-tooth equipment 
(Table VII) average only half that of spike-tooth harrows, it appears 
that the draft of this type of implement on the soils where it is used 
is twice that of the smoothing harrow on the soil where the latter is 
found practical. The spring-tooth harrow is better adapted to 
stony soils, where the ordinary harrow would not work well. For 
2-horse, 3-horse, and 4-horse teams the acreage per horse decreased 
somewhat and the acreage per foot of width increased to some 
extent as horses were added, indicating that a width over 2\ feet 
per horse is generally an overload. On freshly plowed land each 
foot in width should cover from "1.2 to 1.5 acres daily and each horse 
could conveniently draw from 2\ to 2 J feet in width and cover 3 to 3.25 
acres. On well-packed land each foot hi width could be expected 
to cover from 1.4 to 1.7 acres daily and each horse from 3.5 to 4 
acres. About 20 per cent less can be done on freshly plowed than 
on well-packed soil. This is doubtless due more to the poor footing 
and consequent high stepping, which tires the horses, than to any 
difference in draft. With increasing width the daily duty of spring- 
tooth harrows increases only half as fast as that of the spike-tooth 
harrow. 
In Table VII the original data for the most common widths have 
been brought together by horses in the team. The table is parallel 
