The balance we should be capable of working out ourselves, such as labor, leakage, cost of gas at consumers' meters, and such other data that we certainly should be more familiar with than any one else. Of course, the fuel gas will have to have an odor, and must be delivered at a proper pressure; and proper appliances for governing supply and insuring perfect safety will have to be calculated on. In fact, the gas man must try to improve on methods adopted, and do his best to hasten the day when solid fuel in our homes shall be no more--in other words, we have to take hold of the fuel gas business in its infancy or it will get weaned away from us. Mr. McMillin, with others, has given us some figures on fuel gas which have been verified by practical tests. For instance, he gives us as his opinion that a mixed gas is more adapted for all-round purposes than either coal or water gas alone. From experiments made we find that from a ton of bituminous coal, making a mixed gas, we can realize as salable gas 63 or 64 per cent. of the total heat units in the original ton of coal, or about 17,000,000 heat units, besides a residue of heat sufficient to produce the steam for making the above amount. Of this mixture 20 per cent. is coal gas, made in the ordinary way, which is the only objectionable feature the writer can see in the process. I am inclined to think that Mr. McMillin rather strained a point here in order not to alarm coal gas men, or else to avoid a too radical change in the apparatus now in vogue for making coal gas. By his statement we find that in water gas, labor and repairs cost but 7 cents per M, while coal gas costs for the same items 15 cents per M. Of course, the proportion of coal gas made by the old method is of more value in heat units than the water gas made by the new method; but what I wished to suggest was this, that if the whole process be made in the cupola as water gas is now made, whether the result would be the same number, or nearly so, of heat units in amount of gas made, with a large reduction in labor making the coal gas cost no more than the water gas for the item of labor repairs. If the mixture can be made in this manner, and I have some assurance that it can be done successfully, then I think it would pay any company to abandon the use of the present style of gas benches, and use the space now occupied by them with more improved apparatus, rather than use them at a loss, simply because we have them on hand. We have pictured an ideal burner for our homes in the fore part of this paper, and I cannot refrain from holding up to your view this ideal fuel, which has no smoke, no dirt, no ashes, and entails on the housewife no extra labor, can be regulated automatically to one steady temperature, and does not require a workingman, after doing a hard day's work, to come home and find a ton of coal dumped on the front sidewalk, which has to be wheeled or carried in before night comes on.