The following table of the comparative value of different kinds of fuel we have collected from various sources, and it embraces the principal results obtained by numerous experimenters, from Count Rumford down to Dana and Johnson. For convenience of comparison we have reduced the several tables all to one common measure, the number of pounds of water heated from the freezing to the boiling point by one pound of the fuel: KtMDB or Fuit. Pounds of water raised One pound, when burnt, will lieat: from 33 to 212. Lime tree, dry wood, 4 years old............................ 34 slirttly dried................................... 38 " strongly dried................................ 40 Beech, dried 4 or 5 year .................................... 33 " stronply dried..............................,----,... 36 Oak, common firewood, in small shavings ............,,.... 26 " the same in thick shavings ............................ 24 Ash, common dry wood..................................... 30 Svcnmore, strongly dried..............,..........,........ 36 Bird cherry, common dry wood ...,......................... 33 Firwood ................................................... 30 Poplar .................................................... 34 Horn beam ................................................. 31 Charcoal.........................................,.......... 68 Peat, French ......................,......................... 18 " Irish.................................................. m Coke, aas coke, from Paris ................................. 60 ** from coal of St. ltienne ............................ 65 Coal, Hpnite fj-om Meiszner ................................ 43 " brown coal from Meiszner............................ 58 " Newcastle............................................. 70 ** cannel cnal, from Glasgow............,............... fifi *v anthracite, from Pennsylvania...................... 69 " anthracite, from Laval......................,......... 74 Rock oil.................................................... 40 Alcohol ..................................,................... 38 Hydrogen................................................... 246 Johnson, by his experiments at Washington, in 1844, found that the amount of water evaporated from 212, by one cubic foot of coal, varied from 440 to 556, with different specimens of anthracite ; from 350 to 478, with bituminous coking coal ; and from 355, with Scotch, to 459, with English bituminous coal. In the English experiments of De la Beche and Playfair, the Newcastle coal varies from 825 to 559 ; and Scotch coals, from 352 to 4G0. OUR review of the patent coal oil suit, noticed in our last number, ia necessarily delayed until our next issue.