blast furnace. It is believed that by an alteration in the form of furnace, this will be no longer an exception. Among the uses which have been proposed for natural gas, is the manufacture of electric-light carbons, and the conversion of iron into steel. Mr. Metcalf also mentions another very important application of natural gas, which, if successful, and it seems likely to be completely so, will work a great change in that branch of work. He says: "All who are familiar with the manufacture of very thin sheets of metal, either iron or steel, know the great difficulty there is in pickling the scale off in order to get a fine finished surface. They know the danger of the acid penetrating through the metal and destroying it. It is a difficult thing to do well, and the operation is one that must be done carefully, and is one that any one who has it to do will be glad to get rid of. The process, for which an application for a patent has been made, consists in annealing fine sheets by bringing the annealing box up to the required heat by the use of the natural gas, and then by a pipe connected into the box, when the metal is hot enough, turning in a stream of the natural gas on to the material and allowing it to pass through, keeping the box hot for some little time, and then allowing it to cool gradually, when the whole mass of sheets come out perfectly clean, as clean as tin, but not as bright, but entirely clean, and, singular to say, though the sheets are very thin and packed closely in heavy boxes, this gas in some way gets in among them all, and they come out perfectly clean and free from scale."

PERMANENCY OF SUPPLY.

The fear lest the flow of the gas from the wells should prove to be only a transient phenomenon has deterred. many manufacturers from going to the expense of making the alterations necessary for its introduction. From the very nature of the case it is but reasonable to suppose that, when an opening has been made in a vein of pent-up gas, it is but a question of time how soon the pressure will be relieved and the flow cease. In the case of every well that has been opened a diminution of both the volume and force of the flow has been observed, and the tendency has been towards ultimate extinction. It was very desirable, therefore, that a careful examination of this feature of the gas supply should be made. The history of a large number of wells has been examined with reference entirely to this. The following data regarding the wells drilled by a large manufacturing establishment for the supply of its own works are of interest in this connection.

No. 1. Has been in use nine years, and is still a good well.

Four years in use, still flowing, though with diminished force. Its location is three miles from any other gas belt.

3. Yield insignificant.

4.

5.

6.

7.

8.

Pressure diminished from one and a half pounds to 0 in one week.

Failed after four years' use.

In use six years, gradually failing.

Failed after five years' use.

Good yet. Drilled in 1883.

"11. A good well. Gas struck within a few days.

These wells are all in Butler County, and the partial failure of some of them may be attributed to the close contiguity of numerous oil wells of that district by which they have been drained. The failure in other wells which have ceased to flow, or flow with largely diminished force, may be attributed, in some cases, to their being choked by deposits of salt or paraffine. These obstructions have, in some instances, been removed with entire success by the use of explosives. A number of gas wells are now in full blast, having apparently suffered no diminution, and have so continued for twenty years or more. One in Venango has furnished both fuel and power by its own elasticity for twenty-three years, showing no diminution. The wells at New Cumberland, West Virginia, have supplied gas for more than twenty years for the manufacture of brick. The East Liverpool wells have been burning twenty-five years, and are still productive. The gas wells at Fredonia, New York, which have already been alluded to, have been pouring forth a continuous stream for sixty years. In Beaver County, at the mouth of Raccoon Creek, three miles below Philipsburg, there is a manufactory of salt. The brine is evaporated and the engine worked by the fuel supplied from the gas issuing from the same well that supplies the salt water. This has continued for twentythree years, and there does not appear to be any diminution in the supply of either brine or gas. We have no right, ̧

perhaps, to expect a continuance of the "roarers,'

66

or

gushers," as they are termed, but from the facility with which the gas is reached in a large stretch of territory we may reasonably expect a continuance of supply. It may be necessary, perhaps, to arrange for the storage in capacious gasometers of the supply coming from a number of smaller wells and for its distribution from these. It is the opinion of those who have devoted considerable attention to this that with proper care in its collection and distribution the supply of gas to Pittsburgh for manufacturing purposes is an assured thing. The large investment of capital is the best evidence that we can adduce of the faith that is placed in it. The number of companies chartered to supply natural gas in Pennsylvania up to February 5, 1885, was 150, representing a capital stock of $2,160,580. Since that date a large number of new charters have been granted.1

The subject of the enormous waste of this valuable material has attracted much attention, and, in all probability, stringent laws will be enacted regulating the opening of new wells, and for the prevention of this waste. It is stated upon good authority that more gas is being wasted within twenty-two miles of Pittsburgh than is being used. It has been estimated that 65,000,000 to 70,000,000 cubic feet of gas are going to waste daily in the Murraysville district alone.

1 Report of Engineers' Society of Western Pennsylvania.

NATURAL GAS AS AN ILLUMINATOR.

The chemical analysis of the natural gas coming from different localities, although varying considerably, shows that the deficiency in the carbon element renders it vastly inferior in luminiferous properties to gas manufactured from coal. It really possesses only about one-half of the lighting power of average coal gas. For all other domestic purposes, besides this, it is admirably adapted. The complete avoidance of dust, ashes, and coal carriage is gratefully welcomed in a city where smoke, smoked ceilings, smoked walls, dingy paint, rendered so by the soot and sulphurous fumes, were on every side the rule. Attempts have been made to remedy the deficiency in illuminating power by supplying to the natural gas, carbon, in some form. It has been suggested to mingle with it some of the heavier hydro-carbon vapors, but we are informed that these experiments have not as yet proved successful, as these heavier hydro-carbons are prone to separate in layers at the lower part of the gasometers. Considerable attention has also been given to the alteration and improvement of burners. Experiments are in the right direction here, and when the low price of the gas is taken into consideration it may be quite possible to obtain the same amount of light from gas having one-half the illuminating power by burning twice the number of cubic feet.

Explosibility. A number of accidents have occurred, some of them of a serious character, resulting from the explosive nature of this well-gas, which has caused many persons to view its introduction into general use with grave