336 Chronicles of Science. | April, 
attached the connecting-rods, marked 3, 4; one working the slide 
valve, the other acting by levers 5 and 6, giving motion to a ratchet- 
wheel, which, acting on a system of tooth-wheels 10 (see end eleva- 
tion), cause the piston and borer to make a quarter of a revolution. 
These levers are worked at each stroke by means of projections on 
the piston-rod 1:1. The revolutions can also be effected by hand, 
through the wheel and connection, 9; and this marks the main differ- 
ence between the machines of Crease and Green—the former having 
only the means for making the revolution by hand. 
At the same time that the borer makes its quarter revolution, the 
screw 11 is caused by tooth-wheels to make an equal turn, giving a 
forward motion to the cylinder, and bringing the borer more into the 
hole. 
This machine can be worked by either steam or compressed air, 
the latter being the most convenient, and at all times to be preferred, 
especially in driving the badly-ventilated end of long levels. 
These notes and the accompanying drawing will show that the 
borer can be placed in any position with regard to height or direc- 
tion in a horizontal plane. There is also a joint Fig. 1-12, by which 
it can be adjusted in any direction in a vertical plane. 
We are informed that Mr. Crease’s boring machine has been 
recently introduced in two mines near Tavistock, and we know that 
experiments are being tried in some of the lead mines of the North 
of England, and in the copper mines near Camborne, Cornwall. 
Another boring machine for “driving tunnels, mines, adits, shafts, 
quarries, &c.,” has been constructed and patented by Mr. George 
Low, of Newark. In its more important features it does not differ 
materially from that already described. We are informed that Mr. 
Low’s machine has been applied with success by the Connoree 
Mining Company. The machine can be made with one, or any 
number of borers, which, on an average, will bore holes at the rate 
of two inches per minute, as proved by actual trial. We hear of 
several other machines, some to be worked by air or steam, or by 
water pressure, and others to be moved by manual labour. The 
attention which is now being directed to the important question of 
relieving men from the severe tasks of boring rocks in the confined 
ends of levels, appears likely to result in the production of some 
simple and efficacious mechanical arrangements. 
The advantages of employing machines of this class are great: 
economy in working should at once recommend them to the mine 
proprietor, and on ‘the score of humanity, as removing from living 
muscle its severest toil, and giving it to unwearing metal, the 
philanthropist should urge their introduction. Another advantage 
would be gained by using compressed air machines; the impure air 
of the levels would be dispelled by the escape of that which we had 
used to bore our rocks. 
In a journal such as ours it is important that we should preserve 
a record, easily available, of the progress of our special industries, 
The report of the Registrar-General on the census of 1861 enables 
