COMPOUND-ENGINE STEAM SHIPS.

Nelson Evening Mail, Volume VI, Issue 9, 11 January 1871, Page 4

COMPOUND-ENGINE STEAM SHIPS.

One of tbe reasous assigned by the Government of Victoria for not coming to any permanent arrangement with New Zealand in reference to the San Francisco steam postal line, was that certain recent discoveries in ship-building were likely to revolutionise the system of oceau steam commuuicatiou, aud that as a steamer was expected from London fitted with engines on the new principle, it might shortly be demonstrated that a line of steamers could be run more advautageously for Victoria via the Cape of Good Hope. The vessel alluded to by the Victorian Government was the Queen of the Thames, and the following description of her sister-ship, the Australia, furnished to the Chief Secretary of Victoria by Captain Gilmore, who saw her at Point de Galle, may prove interesting : — " The Australia, 3600 tons register, 401 feet in length, with engines of 650-horse power nominal, but working up to 3000, was built by Caird & Co., of Greenock. She has splendid passenger accommodation, and lately passed through the Suez Canal into the Red Sea, drawing L9h feet water. " The most remarkable feature in this fine ship is the construction of her engines, which are designated 'compound,' for the reason that steam is worked .-it both high and low pressure. There is one small cylinder and one large, bearing a proportionate diameter to each other of 68 to 98. The steam is admitted to the small cylinder at a pressure of about 451b5., and after a stroke of the piston rod passes into a chamber or jacket which surrounds it, and thence into a iarge cylinder, where it is worked at a low pressure, so that by this process the steam is made available twice over. "A much smaller^uantity of fuel is required for generating'steam worked in this manner than was necessary with the old form of engines, and in this particular therefore, a very considerable sayiug is effected. "The engines and boilers of the Australia are fitted with surface condensers, super-heaters, and every modern ipmrovement, and from Suez to Galle the average rate. of speed of the ship was lOf- knots per hour, attained by a consumption of 35 tons of coal per day of 24 hours. "A steamship of the same power and size, with the ordinary construction of engines and boilers, would consume at least 60 tons of fuel iv the same time. The Australia can carry in her bunkers 1000 tons of coal, having still room for 2000 tons of cargo in her holds. " This ship is the first constructed by Caird & Co. on the compound principle, and even better results are expected Irom others upon which they are now engaged."