other places, where there are large assemblies, and where it is very desirable to reduce the suffering from the heat, that cooling arrangements are desirable, and the questions coming in are very difficult to handle. The lowering of temperature by artificial means is a very broad subject, and I am not prepared to say that I am very sanguine of success in artificially cooled temperatures. If the entire air supply could be kept at a uniform. temperature, that would be something desirable, but to have to come from a low temperature to a high would create results that I am satisfied are utterly unlooked for and results that would probably kill the scheme. But cooling within a reasonable range can be done. My own idea of cooling a room of this kind would be that there should be a maximum volume of air at a very slightly reduced temperature, the volume of air creating the cool effect on the body without having extreme changes of temperature.

Mr. Eisert: I made just the very point in the paper that the air should not enter the room at a lower temperature than six degrees, and then entering near the ceiling it will spread out and uniformly settle down, so that a uniform temperature of about 70, 72 or 73 degrees is maintained in the room.

Mr. Payne:-In regard to Mr. Jellett's point of its being injurious to go from a low temperature to a high, if the room were cooled ten degrees below the outside temperature, I hardly think it would be as injurious as to pass to a room heated to 70 degrees as to an atmosphere of 30 or 35 degrees below zero. We have this up in Canada and heat our houses to 70 degrees when the outside temperature is 30 to 35 degrees below zero. It does not seem to kill anybody up there.

Mr. Jellett:—In answer to that I would say that a man who goes out in a temperature below zero wraps himself up well. Here I am speaking of summer temperature where a man with an alpaca coat steps into a much lower temperature without putting on an overcoat. The conditions are entirely different.

Mr. Payne:-Let him suit his clothing to the variations of the temperature, reversing the process.

Mr. Fish--I agree with Mr. Jellett. Let the thermometer on the piazza drop five degrees and he will take off the alpaca coat very quickly and put on something quicker.

Mr. Cary: I think that the whole matter of heating and ventilating here resolves itself into depriving the air of its excessive moisture, and if we do that and have a drop in temperature of four or five degrees, we get the looked for results and that is about all that is needed. But it is quite a difficult problem to take care of the

moisture in the air and deprive the air of its moisture, and that is the problem which I think we will have to tackle. In these western cities I understand that they do not attempt to cool the air more than ten degrees. The report came from Kansas City that where the temperature inside is only six degrees below the temperature outside, the people come in there and are perfectly satisfied.

Mr. Hoffman:—I perfectly agree with the gentleman who just spoke from an experience that I had in the West 15 or 16 years ago. I was on the plains in the cattle business in southern Kansas. We used to have temperatures there that would run up to 112 and 115 degrees in the shade, and I never felt the heat there anywhere near as badly as I have felt it in New York at 88, and I have always attributed that, since I knew anything about the laws of heating and ventilation, to the relative difference in humidity of different atmospheres; that the whole thing was simply in the humidity of the air. The air out West was almost entirely dried of its moisture and I had no sensation of discomfort at all. I have ridden all day, with the sun shining right on me, after a drove of cattle that was creating a big dust, and I never had any sensation of discomfort so far as the heat was concerned.

XX.

SCREWED FITTINGS FOR HIGH PRESSURE.

BY HUGH J. BARRON.

(Member of the Society.)

One of the most remarkable things in the development of the use of iron pipe has been the standard fitting and standard thread, both of them depending primarily on the standardizing of wrough iron pipe. When we come to think what the pipe industry would be without these standard articles, we begin to think it marvellous that they have been devised and that an agreement in regard to standardizing was reached so early in the development of the industry. Standard articles of every character tend tremendously to the cheapening of their production and thus fill an economic necessity, but this very advantage has its drawbacks; with standard fittings the great difficulty to-day is that the refining process of cheapening production has gone so far as to call for a reaction in favor of special fittings for special work, and the purpose of this paper is to advocate the manufacture of wrought iron or wrought or cast steel or malleable iron fittings for screwed work for heavy pressures and for all large pipe work except that used for very low pressures. Forged fittings are so much more reliable, so much surer in every way, that it is strange efforts have not been made to displace the cast iron fittings. When the fittings that are now in use were designated, low pressures and small sizes of pipe were the rule. Within a few years the conditions have changed; high pressures are now the rule, and large sizes of pipe in connection with large power plants are no longer the exception. The changes that are required by modern conditions are confined to ells and tees and to sizes larger than three inches; all other fittings. I believe, are safe and satisfactory, and the smaller sizes of tees and ells are not seriously objectionable, even at high pressures, but the ordinary 6-inch ell or tee at 100 pounds pressure is decidedly dangerous, and the engineer who does not feel nervous when he is close to one of these fittings when there is water hammer and heavy pressure combined must be verv courageous or very reckless. When the various strains that

such fittings are subjected to are considered, instead of the usual factor of safety of six being present, there is absolutely no factor of safety at all, or the factor is so slight as not to be worth considering; first there is the pressure, then there is the pressure or tension set up by the taper thread when it is jammed in by the fitter and the chain tongs-this is a constant strain tending to burst the fitting-then there is the shrinkage strain of the casting, slight of course, but must be considered as increasing the complexity of the tension on the fitting. To these add the strains due to the expansion of the pipes and the tremendous strains due to the blow a fitting receives when water jumps into a partial vacuum, and is it any wonder that fittings burst? Blow holes and imperfect castings add to the danger and unreliability of cast fittings; the marvellous thing is that there is not more trouble from this cause, but as pressures continue to go up this trouble will increase. None of the ordinary ells and tees above four inches in size should be used for pressure above 50 pounds. These remarks do not apply to flanged cast fittings, and many get over 'he difficulty of the screwed cast fittings for power work by specifying and using flanged cast fittings and flanged cast pipe or wrought iron or steel pipe with cast flanges, but I am inclined to think that there is a better way of overcoming the difficulty; that is, either make cast screwed fittings for power work twice as heavy as they are made to-day or substitute forged fittings or cast steel or malleable fittings. I am one of those who do not like flanged joints if they can be avoided, and I believe that, with the proper fittings, screwed joints are far more satisfactory. The question of pipe and fittings for high pressure steam is outside the scope of this paper, but that there is room for improvement in ordinary power piping is evident by even a slight examination of any large plant. Engine builders some years ago, in order to get the initial pressure in their cylinders as close as possible to boiler pressure, advocated long sweep fittings, similar to hydraulic or hot water fittings. Some engine builders made patterns for these fittings that were extra heavy, and I think with a sufficient factor of safety, but I am inclined to believe that a forged wrought iron fitting would be the best, and to have the pipe work almost entirely wrought iron, that is, the fittings and even the valve bodies forged, would be the safest for high pressures. A possible solution of this problem may be in the gradual introduction of malleable steam fittings of heavy pattern for steam work. I have used such fittings for many years and have always found them satisfactory, but the larger sizes are entirely

too light for present day pressures. If, in addition to the standard flanges which have been adopted by the trade we had a standard ell and tee it might possibly be a step in advance. I am averse to advocating special measures of this kind, as I am afraid they interfere with the natural development of the best device, or have a tendency to do so, but I do not believe any harm can be done by condemning the present cast fitting for high pressure; they have outlived their usefulness and we need a substitute for them.

DISCUSSION.

Mr. Cary:—Mr. Barron seems to lay a good deal of stress on the point that steam pipe ruptures of late are attributable largely to the poorness of the fittings, the lightness of the fittings. I cannot agree with him in every respect. Take the accident that recently occurred on board the St. Paul, and the other accident at Hammerstein's theater-I do not think that wrought iron fittings, cast steel fittings, or anything else would have withstood the rush of water into the vacuum. If you have a large cold steam pipe, open your valves suddenly, and allow the steam to rush into the cold space, a lot of water is immediately produced by condensation, and this is carried on by the velocity of the steam rushing into a chamber of much lower temperature, carrying the slug along until it comes to a change of direction and there it is pretty sure to carry out anything in front of it. The matter of adopting forged fittings is very good if you can get people to pay for it. But I believe I should be ruled out on that, as I said the other day that we should not stand on the cost of work that is done by the members of this society; that we should advocate good work, whatever it cost and try to educate the peoplè up to it. But at the same time I am afraid that forged fittings would be very expensive and almost prohibitory. The matter of casting fittings is now being done by several concerns and they are producing very good fittings, giving much better results than the others and doing away with couplings. I saw a few days ago that a concern in Pennsylvania is rolling up the ends of the pipes in a manner somewhat similar to expanding; they swell the pipe up and roll it right there and make a flat flange. It is done in Pennsylvania. I am sorry that I cannot give the name of the concern. It is represented by Mr. Charles A. Hagne.

The President:-It is Best, Fox & Co.

Mr. Cary:-That is the name. The more we can do away with fittings and produce pipes with the ends brought up this way into a flange the better we will be off. I think that is a step in the right