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POPULAR SCIENCE REVIEW. 
Washngton, U.S., for a rotary rock-boring machine, which is of an ingenious 
kind. It consists of a drill composed of a number of scalloped cutting-wheels, 
which are arranged on a common head, on axles passing through said wheels 
at right angles, and in such a manner that by giving to the head a rapid rotary 
motion, the wheels will cut into the ground or rock and produce a clear hole. 
The dirt or dust is raised by the action of a spiral flange, secured to the out- 
side of the drill rod, and guided by conveniently arranged friction-rollers. A 
stream of water is made to pass continually to the bottom of the hole through 
the drill rod, which is made hollow for that purpose. Much of the dirt is 
thus removed. The machine can be applied to ordinary rock-drilling or well- 
boring. 
A new Oil Well in Russ ’ f has been discovered in the district of the Natu- 
chaitz, on the shore of the Caspian Sea. After boring a depth of 120 feet in 
solid rock, a stream of oil made its appearance, and flowed for twenty minutes. 
This was followed by a deafening noise, accompanied, it is stated, by a 
slight earthquake, after which, a jet of clear water, very saline, burst forth, 
with great violence, and continued running for nearly half an hour. Since 
then from 1,500 to 2,000 pailfuls of oil have been drawn out. — Vide Colliery 
Guardian, April 7. 
How to Prevent Explosions in Coal-mines. — We sincerely wish that the pro- 
prietors of collieries would adopt the following sensible piece of advice which 
Mr. G. Adcroft, of Barnsley, has published in a late number of the Mining 
Journal. In the first place, he says that in mines where there is gas, lamps 
should be used exclusively, and not a mixture of candles and lamps, as is 
often the case. The lamps used should be Stephenson’s ; for the Davy is not 
safe. All lamps should be bought by and belong to the employers. The 
material of which the lamps are made should be of the best possible quality 
that can be obtained. They should be made in the best possible manner, with 
the best possible workmanship. They should be cleaned every day with flint 
dust by men and boys employed by the masters. The lamps should never be 
allowed to be taken from the pit by the men ; they should be given to them 
in the morning locked, and delivered up at night in the same manner. If 
any one in the mine happens to have his light put out, he should be compelled 
to come to a certain place to have it re-lighted. Neither a manager, viewer, 
deputy under-looker, nor any other person, should be allowed to have a key to 
unlock the lamps, except those stationed at proper places. “ I speak particu- 
larly upon this point,” he says, <4 because I know from experience that even 
deputies and managers have been imprudent at times when they have been 
allowed to have a key, and have unlocked lamps where there have been 
explosions caused through it ; whereas, if they had not had a key they could 
not have done it. A painted rule should be fixed at the top of the pit, 
where it could be seen by all the workpeople, stating that if any matches or 
pipes were found upon any workman’s clothes he should suffer imprisonment.” 
