In all gas works of any magnitude, a considerable quantity of fuel must be employed for the purpose of supplying the works with steam for the exhauster engines, chemical apparatus, thawing purposes, etc. Whether this fuel consists of coke or of coal, will not in the least affect or alter my figures. I have no doubt if any manager discovers that he is working more economically by selling the coke and using a cheap small or other coal, he will adopt the cheapest process. In Dundee, where we get a good price for coke, I found, for the purpose of steam fuel, it would be far cheaper to buy small coal costing from 5s. to 5s. 6d. per ton delivered in the works, and dispose of the coke. The question of fuel then lay between coal and tar; and I have experimented somewhat extensively to ascertain the true relative values of the two classes of fuel. For the purpose of this paper, and within the last few days, I made a further examination into the question; and the results arrived at will be those here quoted. The coal we employed was what is known as Stravenhouse small coal, which costs 5s. per ton delivered. The experiment in each case lasted 48 hours. The tar employed was what is known as boiled tar; the naphtha having been previously removed, but the pitch oil left in the tar. The value of this tar in Dundee is about 4s. per ton. The following are the figures: Coal, 10 tons 16 cwt., at 5s. £2 14 0 Tar, 1,460 gallons (or 9 tons 3 cwt. 160 gallons = 1 ton), at 4s. 1 16 7 ------- Saving per day by using tar. £0 17 5 And this at the longest day, when we are using a mere fraction of steam, as compared with our winter requirements, and consequently the profit is proportionally less than it will be when we are in full work. [Illustration]