Five Years' Pror/ress of Steam Cultivation. 383 
Most of the figures have been calculated from data given in the 
gross in printed reports from purchasers and employers. Some 
of the items are, of necessity, more or less arbitrary ; some few 
sums are matters of estimate ; and in one or two instances the 
cost price of the machinery is incorrectly stated for want of pre- 
cise information. Perhaps I have committed some mistakes in 
characterizing the soil of particular farms, and in stating the 
number of horses there required in a common plough. Other 
errors may exist, though unknown ; but the general truthfulness 
of the details may be relied on, and the final averages may be 
taken as fair data of practical steam culture in many difl'erent 
hands, and under very various circumstances. Removals and lost 
time are principally accounted for in the sum for wages, &c. ; but 
in some instances a small addition ought perhaps to be made 
for horses, reckoning one removal (occupying say one-sixth to 
one-fourth of a day on an average of distances) due to about 20 
to 24 acres, — as computed from a number of still later reports 
recently published. 
The sums for rope and repairs are nearly all founded upon the 
outlay actually incurred ; or (where the experience has been too 
limited) are charged in about the proportion averaged by the 
cases of longer experience. But the amount of "depreciation," 
or, in other words, the sum to be annually laid by for replacing, 
or, in other words, maintaining the machinery perpetually in 
good condition, has not been so well ascertained as the cost of 
rope and other working parts worn out or broken. Steam-ploughs, ■ 
more particularly those with self-travelling or locomotive engines, 
have not been in existence for a sufficient time to show how long 
they will really last. The market value of a second-hand engine 
and set of tackle is, of course, no guide here, seeing that 25 per 
cent, of the cost price may sometimes be sacrificed by only a 
day's work (not from damage incurred, but from becoming 
" second-hand " instead of " new ") ; and while minor improve- 
ments are being continually added to each invention, purchasers 
will seek the newest form out rather than buy an old machine at 
half-price. For the sake of being over rather than under the mark, 
I have supposed the engine and apparatus, though every year 
repaired as far as wearing-parts and breakages are concerned, to 
become good for nothing and not worth a farthing at the end of 
ten years. I suppose the metal-work to rust and consume away, 
and the wood to decay, so utterly that a completely new " set" 
must be purchased every tenth year. Competent judges agree 
with me that this is an extreme supposition, and that I have con- 
sequently made the cost of work a shilling an acre, more or less, 
greater than a lengthened experience will hereafter prove it to be. 
VOL. XXIV. 2 C 
Still 
