weight of coke, which in the ordinary beehive ovens from coal of the same quality is only 60 per cent. or in beehive ovens having bottom flues about 66 per cent., while in the Carves ovens it is, as I have said, upward of 75 per cent.  Against these figures there is a charge of 1s. 4d. per ton of coke for additional labor, including all the labor in collecting the by-products; the interest on the first cost of the plant, which is considerable, and probably some outlay for repairs in excess of that in the case of ordinary ovens, has also to be charged.  Mr. Jameson takes credit for the combustible gas, which is used up in the Carves ovens, but which remains over in his process, and is available, though not nearly all consumed, in raising steam for the various purposes of a colliery, including, no doubt, before long, the generation of electricity for its illumination.  It is right to state that prior to 1879 Mr. Henry Aitken had applied bottom flues for taking off the oil and ammoniacal water to beehive ovens at the Almond Ironworks, near Falkirk.  He states that the largest quantity of oil obtained was eleven gallons, the specific gravity varying from 0.925 to 1.000, and that the water contained a quantity of ammonia fully equal to 51/2 lb. of sulphate of ammonia to the ton of coal coked.  The residual permanent or non-condensed gases were allowed to issue from the end of the condenser pipe, and were burnt for light in the engine-houses, but it was intended to force them into the oven again above the level of the coke.  Owing to the works being closed, nothing has been done with these ovens for some years.  I may mention, by the way, that it is proposed to apply the principle of Mr. Jameson’s process to the recovery of oil and ammonia from the smouldering waste heaps at the pit-bank, by the introduction into these of conduits resembling those which he applies to the bottom of the beehive oven.  There is every reason to expect that one or more of these various methods of utilizing valuable products which are at present lost will be carried to perfection, and will tend to cheapen the cost at which iron can be produced, and still further to increase its consumption for all the multifarious purposes to which it is applied.

WONDERFUL USES AND DEMAND FOR IRON AND STEEL.

But the world’s annual production of 20,000,000 tons of pig iron is itself sufficiently startling, and without attempting to present to you the statistics of all its various uses—­for which, in fact, we do not possess the necessary materials—­the increased consumption of more than 9,000,000 tons since 1869 becomes conceivable when we consider how some of the great works in which it is employed have been extending during that or even a shorter interval.  And of these I need only speak of the world’s railways, of which there were in 1872 155,000 miles, and in 1882 not less than 260,000, but probably more nearly 265,000 miles.  In the United States alone about 60,000 miles of railway have been built since 1869—­the year, I may remind you in passing, in which the Atlantic and Pacific States of the Union were first united by a railway; while in our Indian Empire the communication between Calcutta and Bombay was not completed till the following year.