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Some of these new American oil field instruments are finding application in other industries.  The coal measures in parts of Belgium, France and England are over-lain by strata so porous and so full of water that shafts cannot be sunk through them with the use of pumps.

Shafts are now being sunk in a very ingenious way.  A ring of bore holes is drilled around the location for the shaft. Pipes are inserted in each hole and for many weeks refrigerating fluids are pumped through them.  In this way the shaft location is converted into a huge solid block of iron-hard ice.  The miners then blast the shaft through the heart of this ice core and not until [[strikethrough]]it[[/strikethrough]] ^[[the shaft]] is completed and lined with steel and cement can the circulation of freezing fluid be discontinued.

Precise bore hole survey instruments are used in locating the underground position of ^[[each of]] the ring of holes referred to above.