and 50 tons have driven 39 feet of tunnel, at a cost for coals of £47-10-0 which equals about £1.4.4 per foot run (This work was done in 13 days. 22 hours).
Wish Coal.
Welsh coal costs 28l. per ton, and 50 tons have driven 40 feet of tunnel at a cost of £50, which equals £1.15.0 per foot run (This work was done in 14 days. 21 hours). The relative times worked, and lengths driven do not materially affect the cost. It appears according to these trials that Welsh Coal costs 18s. per foot run more than Japanese coal.
Taking the above statement as it is put, I am bound to sanction a use of Japanese coal. There is, however, the well-known fact that Coals Long Exposed, deteriorate to a considerable Extent. As Exemplified by Cool au Escape of gas in a ship's bunkers when an Explosion takes place: as also when Stored in bulk by firing in the centre.
It is stated that there are about 40,000 tons of Welsh Coal in store in the Colony, and my Experience with Coal leads me to the conclusion that there must be great loss in these stores under the best conditions with occasional Serious loss during wet weather if the stores of Coal are Exposed. These facts account for the superior results obtained from an inferior coal when used comparatively new from the mine and without long Exposure in bulk.
As to the purchase of Portland cement in the Colony, I do not see how I can interfere without, in some degree delaying the work, and the completion of the dam wall is of Such importance that I do not like to do this. I must however assume that the Surveyor General will not use dead or bad cement.
The Tunnel.
The completion of the tunnel is essential to the use of the works. Water may with Safety be impounded before the Key ...