for reasons given, we were unable to keep the benches in steady and uninterrupted work.

This is clearly shown in results obtained for the month of June, when 76 per cent. of the gas manufactured was made in the new benches with a less number of charges missed during that month than in the statement before us for the nine months.

During the month of June there were carbonized 971,272 pounds of coal, which yielded 5,235,156 cubic feet of gas; the average yield was 5.39 cubic feet of gas per pound of coal carbonized.

The average number of retorts in use was 161⁄2; the average charge of coal per retort was 327 pounds; the average daily make of gas per retort was 10,576 cubic feet; and per bench, 63,450 cubic feet; four per cent. of cannel was used, and the gas 19.5 candles; the production was 206,232 candle feet per retort, and 1,237,275 candle feet per bench per day.

The furnaces are easily operated and fully under control; and, with proper attention, result in almost entire freedom from clinker. If a continuous supply of water is kept in the ashpan the fires will not require clinkering oftener than once in 5 or 6 weeks; but if the ashpans are allowed to become dry clinker will accumulate rapidly, and in an hour or two the fires will be choked.

Our record shows that the fires of the three benches, charged on December 11, 1884, and in continuous use up to the present time (Oct. 7, 1885)—a period of 300 days-were clinkered ten times only-or on an average of 30 days-during which time we had four interruptions to our water supply, and, in consequence, were obliged to clinker the fires in 12, 23, 11, and 27 days, respectively. The average time, exclusive of the four occasions mentioned above, was 3723 days, or 5.38 weeks.

The longest period over which we allowed the fires to run without clinkering was forty-four days. When clinkered the grate bars are drawn and fires let down. The clinker mass is found in a rotten condition—i. e., it can be easily broken up and detached from the sides of the furnace. After the three hundred days' of use the furnaces are in as good condition, and nearly as perfect, as when built.

The grate bars are likewise in good condition, having never been changed.

Hot coke is fed directly into the furnaces from the two lower retorts in each bench, requiring about 25 per cent. of the coke made to run the fires. One man easily attended to the seven fires we had in use last winter, except on clinkering days, when he required some assistance—say, one-half to three-quarters of an hour for each bench at each time of clinkering. The man in attendance at the fires shakes the grate bars every four hours, removes the ashes from the pan, sees to the water supply, and assists in removing the hot coke into the yard. The fireman, aided by coke yard man, takes care of the hot coke, as it is received from the retorts, until quenched in the yard.

On the charging floor we work one man to each bench in each shift. They handle their own coal, and rake the hot coke from the retorts into cars below.

Thus, I believe, I have fully complied with the President's demands, and will take up no more of your time, hoping that I may be pardoned if I have necessarily repeated portions of my former statement before the Central New York Association.

The furnaces have given us entire satisfaction in every particular.

Discussion.

The PRESIDENT-We have listened to a most practical and valuable paper. It belongs to a class of contributions which, I think, would be much to our interest to have more of. It relates to a subject the consideration of which has done as much to develop the economies of our industry as anything else that has been presented during the last 15 years. I hope it will receive a complete discussion at your hands. There are a number of members present who have had experience with different kinds of generator and recuperative furnaces; and I will call upon some of them to take part in the discussion. I think Mr. Slater has had quite an experience with different forms of furnaces, and has obtained valuable results.

Capt. WHITE-Before the discussion commences I would like to move that 1,000 copies of Mr. Wood's paper be printed and distributed amongst the members; also that illustrated drawings of the furnace be inclosed in the pamphlet. It contains most

desirable information; and the aim of the motion is to save Mr. Wood from replying severally to the many calls that are sure to be made upon him for information in regard to the very matters contained in his paper.

Mr. HARBISON-Mr. Wood, in his paper, states that he had previously read a paper upon the same subject which gave a more detailed description of the construction of the furnace than the one just presented by him. Many members of the Association would be pleased to have that description inclosed in the proposed pamphlet, even though the prior paper has been already printed in the Journal. It might add a few additional pages to the pamphlet, but I think the latter would be more valuable if the Secretary should be instructed to print the former article in connection with this. I therefore move that as an amendment.

Capt. WHITE-I accept that amendment. It was my understanding that that course would be followed, as the paper read last May really forms part and parcel of the one we have just heard read.

Mr. WOOD-The suggestion meets with my approbation, and for the reasons mentioned by Capt. White.

The motion, as amended, was agreed to, and the regular order of discussion resumed.

Mr. SLATER-As most of you know, our experience at Providence, R. I., has been confined almost exclusively to the Dieterich furnace. I do not know that I can give any facts other than those already given by me before the Association on several occasions. Before leaving home I copied from our books an average of the results obtained this year; consequently the statement may show some improvement on what we have done before. At our West Station the lowest average yield for any one month in the present year was 10,984 cubic feet per retort; the average yield per pound during that time was 4.88. The largest yield for any one month (July) was 12,457 cubic feet—or a yield per pound of 5.22. Taking the first six months of the year, the average yield per retort was 11,217 cubic feet—or a yield per pound of 4.90. In the third quarter of this year our average yield per retort was 12,080 cubic feet or an average yield

per pound of 5.23. At the other station (where we have similar retorts) the lowest average yield during any one month was 9,993 cubic feet-with an average yield per pound of 4.92. The largest monthly yield (February) was 10,417 cubic feet per retort-or an average of 4.94 to the pound. I think, in the working of our furnace, there is probably more wear and tear than Mr. Wood experiences with his. He also has less expense for grate bars. We obtain a trifle more gas than he does. He reports quite a percentage of larger yield per retort, but with less candle power.

Mr. WOOD-I think it would add value to the information if Mr. Slater would give the size of his retorts. The Association will be interested with his experience in working three-hour charges with an average of less coal, I think, than we use in our smaller retorts. Still, he burns it off in three hours while we burn it off in four.

Mr. SLATER-I am not able to give, from memory, the square inch surface of the retorts; but they take the same arches as do the 14 by 22. They are what is known as the Davidson retort. Nearly two-thirds of the back end is wider than the front end. They take the same mouthpiece as the 14 by 26. We run threehour charges exclusively.

The PRESIDENT-Have you got figures of coke consumption with you?

Mr. SLATER-No; but I can say that, when the furnaces were new, we have been down to as low as 19 per cent. of coke by measure; when the furnaces become old, however, the percentage is increased somewhat.

Mr. STARR-What weight do you charge?

Mr. SLATER-We are charging from 280 to 315 pounds every

three hours.

The PRESIDENT-I understand that Capt. White has a letter from Mr. McIlhenny, of Washington, who has had a great deal of experience in the erection and manipulation of these furnaces. We would be very glad to hear the letter read.

Capt. WHITE-I have, as you say, a letter from Mr. McIlhenny. Presuming the members of the Association would like