Covered Cattle Yards. 
485 
£ s. d. £ >. rf. 
Corrugated iron roof, first cost (lowest tender) 110 13 0 
Interest on same at 4 per cent, per annum for 
40 years 177 7 6 
Kepairs, ' per cent, per annum for 15 years 
on 1101. 18s 7 1G 3 
Total cost for 40 years 296 1 9 
Board roof, first cost 51 16 4 
Interest on same at 4 per cent, for 40 years . 82 17 6 
Cost of renewal of boards at the end of 
20 years • . . 25 1 0 
Interest on same for 20 years at 4 per cent. 
per annum 20 15 0 
Repairs, 1 percent, per annum on 51/. 1G.«. Id., 
for 15 years 7 15 3 
Total cost for 40 years 1S8 5 1 
£107 16 8 
On the assumption that at the end of 40 years both board 
and iron covering are worn out, we should have a credit balance 
in favour of the former to the amount of 107/. There would be 
the tie-rods and framing of the iron roof as a set-off against the 
main timbers of the board one ; but further comparison would 
be so hopelessly against the former that it would be futile to 
continue it. 
Slate Eoof. 
The roof ranking as the next most costly is the slated one, 
Fig. 1. This undoubtedly is the best type for perfect ventilation 
of yards that I have seen, and, when a little extra cost is not an 
object, has much to recommend it. The following is a com- 
parison between it and the board roof : — 
£ ». d. £ t. d. 
Slated roof, first cost, as per priced quantities 110 3 5 
Interest, at 4 per cent, per annum, on ditto 
for 40 years 176 5 0 
Repairs, i per cent, per annum, on 110/. 3*. od. 
for 15 years 8 5 0 
Total cost for 40 years 294 13 5 
Cost of board roof for 40 years (as above) . . 188 5 1 
Balance in favour of board roof at end of 40 years £106 8 4 
At the end of forty years the position of affairs would be 
this : — Slate roof's requirements as to repairs, not large, but in- 
creasing ; the board one, requiring a new covering, being the 
second. At sixty years an outlay for another sheeting of board, 
and possibly new purlins, would have to be met, while the 
repairs to the slated roof would still be on the increase. 
The following statement (with balances brought forward) 
