58 
Before going under water a diver should accustom himself to the apparatus by breathing through 
it for some little time. Great care should be taken that the filter is thoroughly clean before repacking. 
The diver should be most careful not to xvastc his oxygen, at the same time never io shut it off entirely. Bo 
careful to screw uj) the oxygen valve after using. 
Baird’s Coal-cutting Machine. — On the opposite page is given a sketch of one 
of these machines—the only one in the colony—'which was recently imported by the 
Western Port Coal Mining Company. It is a machine patented by Messrs. Baird, of 
Gartslierrie, Scotland, and said to have been used by that firm with every success for 
a number of years, to work the thin seams of coal in their collieries. 
The machine is mounted on a strong cast-iron plate or frame (A), G feet in 
length, supported on four plain wheels, running on steel rails (about three feet long), 
resting on cast steel sleepers and secured thereto by parallel slips as shown. The 
machine is worked by compressed air, at a pressure of 35 to 40 lbs. per square inch, 
the cylinder ( B ) being, 8£ inches diameter, and 8-inch stroke, running 280 to 300 
revolutions per minute, and constructed to run either way. The crank shaft carries a 
bevel pinion ( C) gearing with a large wheel (D), attached to this wheel is a spur 
pinion ( E ) gearing into a wheel ( F ); the wheels D and E are cast together and run on 
a steel stud fixed to the frame. The spindle on which the wheel F is fixed carries on 
its lower end, under the frame, a gipsey wheel ( G) having live projections for driving 
the cast-steel pitch chain ( V) to which the cutters are attached. The cast-steel jib 
(U) projects from underneath the frame, and at its outer end is a similar gipsy wheel 
(/) for carrying the pitch chain and cutters; the inner end of this jib is bored to lit 
a projection cast on the under side of the frame, and has a worm wheel (,/) cast on it, 
gearing into the worm (K) forged on the spindle ( L) which can be turned round by a 
ratchet handle at either end of the machine, the object of this arrangement being for 
the purpose of enabling the machine to cut its own way into the coal, thus obviating 
the necessity of having a loose end at each end of the stall. Previous to starting the 
machine, the jib is turned round in line with the machine and parallel with the rails 
(one of the wheels carrying the frame being taken off for that purpose); the machine 
is then started, and the jib gradually brought round by the worm until it is square 
with the machine, and has entered the coal to the full depth of the cut (three feet). 
A T-keaded bolt is then inserted in the slot (J/), securing the jib to the frame; the 
traverse motion is then thrown into gear and the machine travels on the rails laid 
down, being kept on the same by the four guides ( U) fixed to work inside the rails. 
The traverse gear is worked by a worm (iV) (secured on the shaft for driving the 
pitch chain), gearing with the friction wheel (0), the friction being regulated by the 
band wheel (P) ; on the same spindle is keyed a pinion ( Q), gearing with another 
wheel (B), the same spindle carrying the capstan wheel (S), round which a chain is 
put twice, the ends of chain being secured to a prop fixed in the stall each end of the 
machine. The fly-wheel ( T) is carried on an extra shaft, running at a greater velocity 
than 
single cylinder, requires a 
greater 
O 
velocity of fly- 
of the machine by 
inches, and it will cut in a seam of 23 to 24 inches thick 
One of these machines has been tried at the Western Port Coal Mining Com¬ 
pany’s Collieries, at Kilcunda, the result of its working being as follows :—The 
machine will hole or undercut the coal (in the seam) three feet in from the face equally 
as well to the rise or dip, at the rate of one foot per minute when constantly working, 
or allowing for stoppages ordinarily incurred; the machine will cut 3 feet in depth in 
the coal, and 130 yards in length in eight hours, requiring for its attendance one skilled 
man and two ordinary labourers. The machine was tried in the fire clay bottom, 
which it cut very well, nearly equal to the coal, the bottom being however free from 
grit and not extra hard. 
Estimating a fair day’s work for a good collier in holing coal, in a 21 to 22 
inch seam, at five yards per day of eight hours, it will be seen that the machine will 
do the work ol 25 colliers, requiring the attendance of three men below and an engine- 
driver on the surface. It is considered that the machine at the above colliery will 
reduce the price of coal-cutting nearly 3s. per ton. 
Crushing Plant of St. Mungo Company , Eaglehawk, Sandh urst ..—This plant, 
erected by Messrs. Middleton and Delbridge, engineers, of Sandhurst, consists of a 
