Illustrated catalogue and price-list of James Macbeth & Co. (1891)
James Macbeth & Co. · James Macbeth & Co. · leaf 17
I i VJ 5-, Rock Blasting by Electricity. i^ TESTING THE BATTERY. … The above cut represents a small electric lamp, for testing the conditionand strength of current in the battery or blasting machine. Heretofore, blast-ers had no means of ascertaining whether their battery was in good order ornot ; and if the blast failed to go off, they were at a loss to know if…
