1868. | Engineering—Civil and Mechanical. 397 
apparently complex, though really simple machine, according to the 
evidence of Sir James Anderson, “saved the labour of eight men, 
and acted upon the rudder with a facility and certainty that no me- 
chanical labour could effect.” The construction of a thoroughly 
effective steam stearing-gear is no easy matter, for whilst the rudder 
should be under perfect command, it should at the same time be 
able to yield if exposed to excessive strain by the action of the 
_ waves. It would be impossible here clearly to describe this 
machine without the aid of drawings, but it may suffice to state that 
the above desideratum is fully accomplished by it ; the rudder being 
capable of yielding, and at the same time returning to the desired 
position when the disturbing force is removed. 
A very clever portable drilling-machine has recently been in- 
troduced by Messrs. Westray and Forster of Barrow-in-Furness, 
which has been designed so as to enable the drill to be worked at 
any angle, and to be used to drill holes anywhere within range of 
the machine when fixed. 
A new arrangement of boring-machine has recently been de- 
signed and patented by Mr. Thomas Greenwood of Leeds, which is 
specially intended for boring gun-barrels, shafting, or other articles 
in which a deep hole is required to be formed. The work to be 
bored is mounted above a tank containing lubricating material, and 
in this tank the drills are placed, the work being bored upwards 
from the lower end. 
Golay’s millstone cutting and dressing machine has recently 
attracted great attention, and large sums have been paid for the 
right to manufacture it im this country. With this machine, 
the “cracks” are cut by a diamond fixed on the edge of a small 
_ dise, revolving at a very high speed, its spindle beng mounted on a 
carriage which can be moved to and fro on the line of the cracks. 
Experiments have recently been made at Chatham, with very 
satisfactory results, to test the merits of a new application of the 
diving apparatus invented by Mr. Siebe, submarine engineer, by 
which two divers can be sent down in any depth of water, and be 
supplied with air from the same pump. ‘The diving apparatus is 
fitted with a self-acting pressure gauge, and the invention can be 
used as a submarine lamp. 
A new method of extinguishing fires by the application of car- 
bonic acid gas, projected from a portable fire-engine, was lately 
tested upon the battery in New York city. The engine is about 
the size of a common garden engine, it is worked much in the same 
manner, and may be operated by two men. When in action two 
cylinders are employed to supply an air-chamber, the pressure from 
which, acting upon the carbonic acid gas formed by the mixture of 
solutions of tartaric acid and carbonate of soda, or other suitable 
materials, forces it through a hose, by means of which it may be 
directed wherever required. 
