STEAM NAVIGATION. 435 the Mining Company in this city proposed to Cap¬ tain Bunker, of the Benjamin Franklin , to take in a supply of coal, and use it, instead of wood, on his trip to Providence and back. He did so, and became so satisfied, not only of its practical usefulness, but of its superiority over wood, that he endeavoured at once to have his furnace altered, for the purpose of using it to more advantage. " The facility with which this coal ignites, and its consequent capabilities of producing steam, having been fairly tested, the next question is, What are the advantages to be gained by introducing it into general use ? We answer, first, the great saving in room occu¬ pied by the fuel; second, by the saving in the cost of fuel; third, by the saving in the weight of fuel; fourth, by the saving in labour in handling the fuel and feeding the furnace ; and fifth, by the absence of sparks and cinders, by which the clothes of passen¬ gers are destroyed, and the awnings of our boats set on fire. " We give the following as the result of the dif¬ ferent experiments which have been made :-— " One chaldron of Sydney coal measures 44 cubic feet. " One cord of pine-wood measures 128 cubic feet. " One chaldron of coal will jet as much water into steam in the same space of time, as three cords of pine-wood. Supposing the Benjamin Franklin to require 45 cords of wood per trip to and from Pro¬ vidence, the space thus occupied by wood is 5760 cubic feet. Fifteen chaldrons pf Sydney coal will