It may be contended that I have taken an extreme case, and that, of course, the snow does not lie for very long upon the ground in the condition in which it fell, and that hourly it is reducing in bulk and weight by being ground up by the traffic, and finding its way in the form of water into the sewers. This may be so, but at the same time it must not be forgotten that the bulk is also being constantly increased by that which is shovelled off the house tops[168] and brought out from private premises adjoining the streets. Upon this point Mr. Hayward, the Engineer to the Commissioners of Sewers of the City of London, says[169]:-- “Snow readily compresses under the traffic, and when removed in carts and shot down elsewhere it may be assumed that on an average four cubic yards of snow measured as it has fallen is equal to one cubic yard when placed on the apparatus.” This computation, however, does not make any allowance for the snow thrown from off the roofs, &c., and it of course greatly consolidates whilst travelling in the cart. Fortunately for a town surveyor in this country, exceptionally heavy falls of snow are not very frequent, but when they do happen great pressure is put upon his department to cope with it, and one of the greatest difficulties he has to contend against is the disposal of the snow after it has been placed in the cart. If there is a river close by, it can be taken there and tipped, but this is objectionable if it is a navigable river where dredging has to be done, as it is surprising what a quantity of road scrapings and other matters are always removed with the snow, and these materials naturally sink to the bottom, and add considerably to the cost of dredging. If there are public parks the snow may be heaped in them, provided no damage is done to the grass or paths, but the snow thus heaped takes a considerable time to melt, the first effect of a thaw being to consolidate it: a better plan is to deposit it upon waste spots, if these are not too far from the streets which have to be cleared. Tipping the snow down the manholes into the sewers has been tried in London and other cities, but has failed through the snow consolidating, and although lighted gas jets have been turned on to the snow, it has still melted too slowly to be of any practical utility. Speaking of Clarke’s apparatus for melting snow, Mr. Haywood, in the same report from which I have already quoted, says: “It is seldom that a fall of snow occurs sufficiently large to cause serious interruption to the traffic; heavy snowstorms in fact occur only once in six or seven years; for some years therefore these apparatuses if fixed might not be required. They would either have to be taken out, stored and refixed yearly or maintained in their places and kept in order there, in either case at an annual expense.”