Covered Cattle Yards. 
483 
them. Openings in the tops of those of circular form tend to 
weaken the structure. 
The one redeeming point which I have frequently heard ad- 
vocated is their economical cost as compared with slate or tile — 
but that I am inclined to believe a fallacy, which will be shown 
later on. 
Fig. 6 shows section of a roof-truss for corrugated-iron roof, 
with principals of tee-iron, with double-apex plates at top and 
shoes for foot of same, with anchor-bolts and double-joint plates, 
purlins of angle-iron, and astragals of tee-iron. The end princi- 
pals to have framing, and the covering to be of best galvanised 
corrugated iron, No. 22 gauge, with circular ventilators. To 
have two wrought-iron columns, with self-fixing bases, rain-water 
gutters, and down pipes. 
Fig. 6. — Corrugated Iron Roof. 
From a firm of respectable manufacturers and erectors of iron 
roofs I have had a tender to supply and fix the same at a cost 
of 130/. From another firm I had, for a similar structure, a 
tender amounting to 140/. 16s. Taking the lowest of these 
tenders, the price per yard of ground roofed over comes out at 
8s. 8d. 
For designs of curved self-supporting roofs of best quality 
galvanised corrugated iron, 18 gauge, with ventilators on crown 
of each span, fixed complete, I had a tender of 120/. 10s., 
and another of 110/. 18s.; at the latter the price per yard 
is 7s. 4±d. 
As bearing on this, I may quote the experience of Mr. Scarth, 
the agent to the Duke of Cleveland at Raby, who has constructed 
a great many of these roofs on the Duke's estates in a very com- 
