Democratic Sentinel, Volume 19, Number 38, Rensselaer, Jasper County, 27 September 1895 — FOR MINE SURVEYING. [ARTICLE+ILLUSTRATION]

FOR MINE SURVEYING.

An Ingenious Arrangement for Signaling Under the Ground. In mine surveying it is necessary to use some luminous object for signaling, as rods eannot be seen. The Colliery Engineer illustrates a contrivance that seems to answer the purpose admirably. It consists of a large brass bob, hollowed out to hold oil and fitted with a top to form a lamp. The bob Is pivoted to a ring, to which

are attacned the supporting chains. By this arrangement the point of the bob, the wick tube and the point of support are always in the same vertical line, even if one chain becomes longer than the other by wearing or by heating from the lamp wick. The sights are taken to the wick tube. In fiery coal mines the flame is protected by fine wire gauze to prevent it from igniting the gas.

TO SIGNAL UNDERGROUND.