tages of proper moisture on the product, the labor performed by the help under the influence of an exhilarating and healthful atmosphere is of a totally different nature to that performed under the depressing and nauseating influence of steam, which is, unfortunately, to-day the method most in use for moistening the air in mills.

In conclusion, I feel it but just to the interests of those connected with the Aerophor to state, that, while not wishing that this paper should be looked upon in any sense of the word as a desire to obtain gratuitous advertisement, they will still be glad to give any further information that may be desired with. respect to this device, and are willing and ready to make equipments for those desirous of making a trial of this system, with the undertaking that, should the apparatus not fulfil the claims made for it, they will remove the same without any charge whatsoever.

I think the officers of the Aerophor Company may, under these circumstances, be justly credited with sincerity of belief in their system, judging by their willingness to substantiate their assertions at their own risk.

Mr. GARSED. Some years ago an effort was made to overcome the trouble from the coal dust under our boilers. The patent called for a number of jets, or sprays of water; which we introduced, through four or six foot gas burners under the grate. We soon discovered that the mucous substance or impurities in the water choked these burners up so that we had to change them three or four times a day; and it looks to me as though a similar result would follow in this case, unless the water was purified by distillation or some means by which you would have pure water, and not be subjected to the liability of choking up the burners.

Mr. KLABER. May I be allowed to state, gentlemen, how the difficulty is overcome? By the peculiar form and construction of the nozzle, the water does not emanate from holes, although apertures are formed that are the equivalent, in every sense of the word, of holes. These nozzles are formed by the laying together of two surfaces. One of these surfaces is grooved, -the lower one, and the upper surface is flat; and, when they come together, an aperture is formed through which the water emanates. But yet, although we use But yet, although we use a larger filter, the fact remains that from time to time the nozzles do become stopped up. The only thing we have to say on this is that the cleaning of these nozzles is reduced to such a simple matter that it gives practically little or no trouble. By releasing a screw, the apertures are exposed, ready to be cleaned or brushed, as may be desired; and in this device forty such apertures can be cleaned at one and the same time. I am not a finished mechanic, but I will undertake to clean one of these nozzles perfectly in two or three minutes.

Then there is another advantage, in addition to the facility with which it may be cleaned, and that is, that the apertures through which the water emanates are smaller than they could possibly be bored. The grooves are made with a very fine watchmaker's file; and, when closed, the apertures formed could not be bored in metal so minutely. The groove is in the lower ledge, and the flat ledge lies on top; so forming an outlet where the groove is.

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Mr. KLABER. From seventy to ninety or ninety-five pounds. The average pressure is eighty pounds.

A MEMBER. How much water is required for an instrument of that nature?

Mr. KLABER. The machine requires about one hundred and twenty-five to one hundred and fifty gallons an hour. After the water has been used, there is a return pipe by which it is led again into the reservoir, and is pumped up and used over again.

Mr. SAUNDERS. I would like to ask you, if a spinner or carder had this apparatus in his room, how he would know when to turn it on or shut it off? If our observations have been of any value, I found that from five to six and one-half grains of water in a cubic foot of air is the best condition to run our mills. The work will run better there than at any other point. Now, how will they know how to regulate it?

Mr. KLABER. Mr. SAUNDERS has touched upon a point which I referred to in my paper. I believe I stated that this is the only apparatus which can be regulated to any extent, and can be shown by a hygrometer. Now, I think it may be interesting to you to hear something of my experience with regard to the hygrodeik. Mr. SAUNDERS has read a paper on the tests he has made with a hygrodeik. I would say here, as justifying these remarks, that I am connected with a business which supplies duplicating devices to the Signal Service of the War Department. We have, by delivering these machines to the government offices throughout the United States, become intimate with a great many of the superintendents of stations; and I may mention Superintendent DUNN of New York, whom I am indebted for the information I am about to gi you. I have found, in visiting many mill men, that have referred me to tests and measurements taken with hygrodeiks, that is, the wet and dry bulb the There is an impression that that is the best inst estimating the humidity in the atmosphere. Now the wet and dry bulb thermometer is the most re

ment that is made for the purpose. The measurements and results that are obtained from it are the most unreliable that can be produced, and the reason of that is this. The results are dependent upon a wet and dry bulb thermometer. The signal office, in taking measurements from this wet and dry bulb thermometer, take that wet bulb and wash it out thoroughly, so that no particles of dust are on it. They have a device by which that thermometer is whirled through the atmosphere for a specific purpose. And yet I have found in many mills that results have been taken and looked upon as reliable, when the wet and dry bulb thermometers have been in such a condition that they would indicate a state of things which never existed. The slightest deposit of dust or fly upon the wet bulb of the thermometer will retard the evaporation of the moisture into the atmosphere, and the comparative reading of the wet and dry bulb thermometer will indicate an incorrect amount of relative humidity. The point raised by Mr. SAUNDERS is a very important one.

Mr. SAUNDERS. Mr. President, in regard to revolving the thermometer, I will say that, in taking readings for the Board of Health of Lowell, during the time when the atmosphere was at the freezing point, I rotated it through the air four hundred times per minute with a machine made for the purpose, and watched it very closely. While I am very much interested in Mr. KLABER'S explanation in regard to the wet and dry bulb thermometer, I must say it is the only instrument we have that we can possibly get in our mills to determine what the atmospheric changes are. Now, by rotating my wet and dry bulb thermometer in the open air, which they do at the signal service in Boston, I find that the difference is very slight from rotating my wet and dry bulb thermometer from what it is in my mill. Of course, if we intend to make application of these papers, and if we intend to get the amount of water vapor that is constantly changing, we must take care of our instrument. It would be useless for us to put a number of hygrodeiks in our mills, and let them run themselves. They must be taken care of, and with a little care they will run very

well. I should say that the minute changes that the signal service observe in making up their weather reports we could not observe, because it would not be necessary, and because atmospheric changes come so often; but we need to keep our atmosphere and humidity within a certain limit. Now, if that apparatus will do that, of course we gain a point; but I think in the first place we must know just about how much we want, and how much we do not want.

Mr. KLABER. We are able to estimate with this machine how many apertures are needed to produce a certain amount of moisture. Of course, the natural conditions of the atmosphere vary; so, of course, to that extent our apparatus is regulable. This is one of those things where experience and good intentions will ultimately come out triumphant. But we claim (and I think I am entitled to state, that in Germany they have succeeded in doing that which we think we will be able to do) to be able to give any man the exact condition of temperature and humidity he may need. We can also warm the water by the introduction of a steam pipe into the reservoir, by which the water, when discharged in the form of water, does not have that coldness that it would have had if taken directly from the reservoir.

A MEMBER. In referring to instruments for measuring the humidity in the air, Mr. SAUNDERS and the other gentleman are talking about scientific instruments. Now, if we had to wet down our clocks in the mills in that manner, I do not believe our overseers would know what time it was. I want to know if they have found a machine that will regulate approximately the humidity in the atmosphere, that I could read at any hour of the day, without any special care except to keep it dusted off, as we would the clock?

Mr. KLABER. We have such an instrument, as I said before, but sometimes it will not act as it should; but, so far as I know, there is not a machine to-day that will indicate the relative humidity more satisfactorily. But we would ask mill men to look at actual results; not to depend so much on measurements, but to see where it is working evenly and