68 Transactions,—Miscellaneous, 
guidance under the different difficulties he has to meet, are at hand to 
support him, 
Thus in this colony, when principles are sought for, they will be found 
to be simple in the main, however complicated the details may be. 
Sanitary works resolve themselves into two distinct systems, namely— 
wet and dry; the former acting by the gravitation of water, the other by 
manual or machine carriage. 
The wet system carries its burden to the sea, or to rivers, when it can 
do this unopposed ; to areas for irrigation in the production of crops ; or to 
waste areas for the purpose of absorption and filtration. The burden may 
also be brought to tanks for precipitation and the purification of the sewage. 
The dry system has its burden carried to the sea, whether by boat.or 
carriage; to the fields for direct application to cultivation, or to works of 
manure manufacture, for all of which the extracts made in the preceding 
part of this paper give examples. 
The separate systems, suitable for the respective situations, are not difficult 
to decide on. Where towns have accessible water-supply and easy exits, 
the wet system is suitable; where these do not exist, the dry system 
becomes imperative. We use the word imperative, because it is in human 
nature for people to divest themselves of that which is disagreeable with 
the least trouble to themselves, and this, when the conditions are favourable, 
is most readily effected by water. But-it has not in all cases proved 
“economical or efficient in the end where water has been had recourse to, 
owing to the nuisance being cast on other interests, and for which the law 
when appealed to has demanded a remedy at great cost. 
In favour of the dry system one great recommendation is to be said, 
namely—that it returns to the soil that which man took from it; thus, that 
it should have a general acceptance by cities in a practical and convenient 
manner, will always be considered a desideratum. 
In New Zealand, more than in almost any other country, the wet system 
is easily available, districts in which a contrary condition exists being 
limited to Canterbury, Southland, and Auckland. 
The proportion of human excreta to sewage is an important question to 
sanitary engineers ; and taking the data afforded by London, it will be found 
that these do not exceed one-hundredth part of the whole sewage. This 
element makes but a small factor in the whole, and is of very secondary 
consideration, under the circumstances of the city possessing a full water- 
supply and a ready place of disposal, such as the sea or a tidal river. But 
in the case of inland towns, where they are forced to purify the sewage, the 
matter is different; for though the excreta there may only form a small 
portion of the whole volume to be dealt with, they perforce form a large 
ININE Rc S BER Saree 
