the saving of fuel that would accrue in these large engines by working them expansively, but have taken the consumption at 9½ lbs. per horse per hour, and with common coal I would have a surplus of 275 tons dead weight for passengers and goods. One objection will, I am aware, be made, viz., that my average speed is too great, and if I admitted that the _beau idéal_ of a steam-vessel was embodied in one of His Majesty’s Mediterranean steam-packets the objection would be fatal; but what is the fact? (no less wonderful than true), the average speed of private vessels far exceeds them; and, to prove that the average speed of 10 miles per hour is not ‘chimerical,’ I may state that the average speed of the _Dundee_ and _Perth_, in all weathers, winter and summer, fair or foul, exceeds 11 miles per hour; that the average speed of the _Monarch_ is 10½ miles per hour; and that the _Medea_ steam-frigate averaged more than 10 miles per hour on her voyage to Malta. Now, I am of opinion that the _Dundee_, _Perth_, _Monarch_, and _Medea_ are to be, and will be, beat, but not by vessels of 800 tons and 200 horse-power. I hope, Mr. Editor, I have proved that it is easier to go from Portsmouth or Liverpool to New York than to the moon; that it is more convenient to go direct than through the first ‘gem of the sea;’ and the last, though not the least consideration, that if we wish to go at all by steam, we had better not wait for the Valentia Railway.” [170] Builders’ measurement, or O.M., is the measurement of a vessel according to the old law of 1773 (13 George III., Chap. LXXIV.) which prescribed as follows: “The length shall be taken on a straight line along the rabbet of the keel of the ship, from the back of the main stern-post to a perpendicular line from the fore part of the main-stem under the bowsprit, from which substracting three-fifths of the breadth, the remainder shall be esteemed the just length of the keel to find the tonnage; and the breadth shall be taken from the outside of the outside plank in the broadest place in the ship, be it either above or below the main wales, exclusive of all manner of doubling planks that may be wrought on the sides of the ship; then multiplying the _length_ of the keel by the _breadth_ so taken, and the product by _half the breadth_ and dividing the whole by ninety-four, the quotient shall be deemed the true contents of the tonnage.”