8 BULLETIN 627, U. S. DEPARTMENT OF AGRICULTURE. 
being influenced by the number of acres cut annually, and the care 
given it when idle. Where a binder covers a large acreage each year 
the acres cut with one canvas may be twice as great as with a binder 
used on only a small number of acres each year, as it deteriorates 
whether used or not. If properly protected when idle, a binder can- 
vas should cut from 400 to 800 acres and perhaps in some cases 1,000 
acres. 
In western New York (see United States Department of Agricul- 
ture Bulletin 338) it was found that it cost nearly 60 cents per day of 
use to keep a grain binder in repair, or 0.058 cent per acre cut, and 
that before a binder is worn out 25 per cent of its first cost, on an 
average, must be spent to keep it in running order. 
The percentage of the first cost represented by repairs is usually 
less for small binders than for the larger sizes, because of the much 
smaller amount of work ordinarily done by them during their years 
of service, while their first cost is only slightly less than for the 
larger sizes. It is believed that 20 per cent of the first cost for six- 
foot binders, 25 per cent for seven-foot, and 30 per cent for eight- 
foot machines will approximate the average repairs required for 
these outfits. Repair charges for six-, seven-, and eight-foot binders 
figured on this basis are shown in Table IV. 
In the eighth column of Table V the approximate cost of binder 
twine per acre will be found. This varies, of course, with the yield 
of straw. The twine required in the West is usually about 23 
pounds per acre, while in the East the average is nearer 3 pounds. 
The cost per pound is generally slightly higher in the West than in 
the East, but it has been figured in all cases on the basis of 3 pounds 
per acre, and as costing 11 cents per pound, which is a little higher 
than the average price in the East during the season of 1916 but 
slightly less than the retail price to the western farmer during the 
same season. 
From the figures given in Tables I to IV, inclusive (to which the 
twine cost must be added, as well as cost for shelter, if any), it is an 
easy matter to calculate the comparative cost of cutting an acre of 
wheat with a six-, seven-, or eight-foot binder. The figures from the 
tables mentioned (excepting the shelter cost) have accordingly been 
summarized in Table V and show that the cost of cutting an acre of 
wheat ranges from 88.4 cents where an eight-foot binder is used to 
$1.173 for a six-foot binder, each machine being drawn by four 
horses. In other words, the expense of cutting an acre of wheat 
with the smaller outfit is nearly 33 per cent greater than where the 
larger binder is used. The figure in which the farmer is most inter- 
ested, however, is the cost per bushel, which is readily found by 
dividing the cost per acre by the average yield. In the last column 
in Table V are given the costs per bushel for the different sized out- 
fits, based on a yield of 16 bushels per acre, which is about the average 
yield for the country as a whole. This shows approximately 7 
