296 
French Experimental Farm at Vanjours. 
gress, whicli teaches us so to increase the primary cost of outfit 
as in a yet higher degree to increase the aggregate of work done. 
The pitcher, the rope and bucket, the haml-j)ump, the horse- 
power, the giant pumps worked by steam, are successive stages 
of development. Whilst a ton of water raised 13 feet by the 
common pitcher costs from 4s. to 5s., when lifted by the drum- 
pump (fij)npan) and 45 horse-power engine on the estate at 
Laissel (near Aries) it costs only l-25th of a penny. These- 
great results are, however, only obtained when the machinery is- 
in full play, or, at least, in pretty constant employ. Steam- 
power far surpasses horse-power if it works from 250 to 300 days 
in a year ; when used from 150 to 200 days the advantage is. 
not so great ; if working less than 100 days its superiority 
vanishes, or is changed into a disadvantage. 
This question of sufHcient employment has been the weak, 
point in our tubular system of irrigation, (generally, where this, 
system has been adopted, the engine, besides devoting 130-150 
days to this work, is employed during the rest of the year in 
thrashing, grinding, slicing roots, churning butter, iScc. At 
Vaujours this course could not be adopted, because it was 
necessary to place the pump and engine on the canal bank,, 
1200 yards from the homestead ; but measures will be taken for 
finding profitable employment for this leisure-time. The chief 
items in the outlay for irrigation being for fixed and moveable 
piping, which cannot be applied to any other purpose, it is an 
important question whether these pipes can be provided with 
sufficient employment, so that the charge for their use may not 
press too heavily on each ton of liquid applied. 
And here it may be observed that the wear and' tear of the 
moveable pipe is proportionate to the work it does, and that 
over the fixed pipe the charge for interest and wear and tear may 
be set at a very low rate, 5 or even 3h per cent, being sufficient. 
The economy of this system, according to English experience,, 
turns upon having a supply of liquid manure proporticjnate to 
the number of acres to which pipes are applied. What, then, is 
this proportion ? 
Lord Essex, one of the most distinguished advocates of the 
tubular system, considers that, when the manure applied is 
derived solely from the urine of the cow-stock, 7 cows, at least, 
per acre are required to furnish the supply. By converting a 
part of the solid into liquid manure, or by the addition of 
guano, these proportions may of course be varied. 
The farm of Vaujours, having the command of an unlimited 
supply of rich manure, is more favourably circumstanced than 
others in this respect. Here, therefore, pipes could, without 
imprudence, he laid under 150 out of 225 acres ; the tax for the 
