Wages of two men and a boy per week, £1 12s.; keep of horses, stables, etc., 18s.; fuel for drying earth, 1s. 6d. per ton dried daily, £1 10s.; cost of earth and repairs, etc., 14s.; weekly expenses, £4 14s. Yearly expenses, £247 (equal to 4s. 11d. per ton per annum); interest, £37 10s. - total, £284 10s., against which should be put the value of the manure. But the value of the manure is simply a question of carriage. If the manure is highly concentrated, like guano, it can stand a high carriage. If the manuring elements are diffused through a large bulk of passive substances, the cost of the carriage of the extra, or non-manuring, elements absorbs all profit. If a town, therefore, by adding deodorants to the contents of pails produces a large quantity of manure, containing much besides the actual manuring elements - such as is generally the case with dry earth - as soon as the districts immediately around have been fully supplied, a point is soon reached at which it is impossible to continue to find purchasers.

The dry earth system is applicable to separate houses, or to institutions where much attention can be given to it, but it is inapplicable to large towns from the practical difficulties connected with procuring, carting, and storing the dry earth.

With the idea that if the solid part of the excreta could be separated from the liquid and kept comparatively dry the offensiveness would be much diminished, and deodorization be unnecessary, a method for getting rid of the liquid portion by what is termed the Goux system has been in use at Halifax. This system consists in lining the pail with a composition formed from the ashes and all the dry refuse which can be conveniently collected, together with some clay to give it adhesion. The lining is adjusted and kept in position by a means of a core or mould, which is allowed to remain in the pails until just before they are about to be placed under the seat; the core is then withdrawn, and the pail is left ready for use. The liquid which passes into the pail soaks into this lining, which thus forms the deodorizing medium. The proportion of absorbents in a lining 3 in. thick to the central space in a tub of the above dimensions would be about two to one; but unless the absorbents are dry, this proportion would be insufficient to produce a dry mass in the tubs when used for a week, and experience has shown that after being in use for several days the absorbing power of the lining is already exceeded, and the whole contents have remained liquid.

There would appear to be little gain by the use of the Goux lining as regards freedom from nuisance, and though it removes the risk of splashing and does away with much of the unsightliness of the contents, the absorbent, inasmuch as it adds extra weight which has to be carried to and from the houses, is rather a disadvantage than otherwise from the manurial point of view.

The simple pail system, which is in use in various ways in the northern towns of England, and in the permanent camps to some extent at least, and of which the French "tinette" is an improved form, is more economically convenient than the dry earth system or the Goux or other deodorizing system, where a large amount of removal of refuse has to be accomplished, because by the pail system the liquid and solid ejections may be collected with a very small, or even without any, admixture of foreign substances; and, according to theory, the manurial value of dejections per head per annum ought to be from 8s. to 10s. The great superiority, in a sanitary point of view, of all the pail or pan systems over the best forms over the old cesspits or even the middens is due to the fact that the interval of collection is reduced to a minimum, the changing or emptying of the receptacles being sometimes effected daily, and the period never exceeding a week. The excrementitious matter is removed without soaking in the ground or putrefying in the midst of a population.

These plans for the removal of excreta do not deal with the equally important refuse liquid - viz., the waste water from washing and stables, etc. As it is necessary to have drains for the purpose of removing the waste water, it is more economical to allow this waste water to carry away the excreta. In any case, you must have drains for removing the fouled water. Down these drains it is evident that much of the liquid excreta will be poured, and thus you must take precautions to prevent the gases of decomposition which the drains are liable to contain from passing into your houses.

There is a method which you might find useful on a small scale to which I will now draw your attention, as it is applicable to detached houses or small barracks - viz., the plan of applying the domestic water to land through underground drains, or what is called subsoil irrigation. This system affords peculiar facilities for disposing of sewage matter without nuisance. There are many cases where open irrigation in close contiguity to mansions or dwellings might be exceedingly objectionable, and in such cases subsoil irrigation supplies a means of dealing with a very difficult question. This system was applied some years ago by Mr. Waring in Newport, in the United States. It has recently been introduced into this country.

The system is briefly as follows: The water from the house is carried through a water-tight drain to the ground where the irrigation is to be applied. It is there passed through ordinary drain pipes, placed 1 ft. below the surface, with open joints, by means of which it percolates into the soil. Land drains, 4 ft. deep, should be laid intermediately between the subsoil drains to remove the water from the soil. The difficulty of subsoil irrigation is to prevent deposit, which chokes the drains; and if the foul domestic water is allowed to trickle through the drains as it passes away from the house it soon chokes the drains. It is, therefore, necessary to pass it in flushes through the drains, and this can be best managed by running the water from the house into one of Field's automatic flush tanks, which runs off in a body when full.