Out of this he made frames to fit the upper half of the school room window and covered them with a light grade of common muslin securely tacked. These were fastened outside the upper sash just as an ordinary wire screen would be.

In the morning, after the rooms are warmed, the upper sash can be lowered and an interchange of air takes place without the detrimental drafts. Neither snow nor rain have caused any difficulty so far.

Last spring we were visited by a Red Cross nurse who was at that time touring the county and investigating the sanitary conditions of the schools. She was profuse in her praise of the fresh, wholesome air condition of the school rooms and of the alert, rosy-cheeked student body resulting therefrom.

LEGAL DECISIONS

Requisites of Claim for Lien.

In proceeding to enforce a mechanic's lien, an intervening claim was made for the heating plant which the intervener had installed in the building. It was objected that the claim did not set forth definitely when the labor and materials were furnished. The claim stated that the clainant entered on the performance of the work on or about December 19, 1911, and did the last work on December 17, 1912. It was held that this was sufficiently definite. But the notice of claim did not state the name of the owner, part owner, and lessee. It was held that therefore it did not support an enforcement of the lien, though the name could be supplied by reference to an attached copy of the contract for installing the heating plant and to the pleadings, since the statutory requirement is that the name appear in the claim. John F. Noud Co. vs. Stedman, Michigan Supreme Court, 160 N. W., 547.

Infringement of Trade-Names.

To constitute infringement of a trade-mark, a literal copy is not necessary, the test being whether the label or mark is calculated to deceive the public and lead them to suppose they are purchasing an article manufactured by a person other than the one offering it for sale. In a suit to restrain unfair trade competition it appeared that the plaintiffs had been engaged in the manufacture of stoves and ranges for many years and had acquired a large business. The articles

It

were sold in connection with certain tradenames which had been registered as trademarks and used continuously by the plaintiffs. The defendant manufactured repair parts for the stoves manufactured by the plaintiffs, on which abbreviations of the plaintiffs' trade-names were stamped in the same manner as the plaintiffs stamped them. was held that the plaintiffs were entitled to enjoin the defendant's use of their tradenames and abbreviations thereof. But there was no question of patent rights involved in the case. The manufacture of the articles without any mark indicating that they were manufactured by the plaintiffs was within the defendant's rights. Therefore a decree restraining the defendant from selling or offering for sale parts for use in stoves manufactured by the plaintiffs without informing that they were not manufactured by the plaintiffs was held to be too broad. Scranton Stove Works vs. C. Clark, Pennsylvania Supreme Court, 99 Atl., 170.

The Testing of House-Heating Boilers.

A DISCUSSION.

The following discussion was presented, but not read, at the recent annual meeting of The American Society of Mechanical Engineers, following the reading of a paper on "The Testing of House Heating Boilers, by Prof. L. P. Breckenridge and D. B. Prentice. This paper, practically in full, was presented in THE HEATING AND VENTILATING MAGAZINE for December, 1916:

PROF. WILLIAM KENT: The method of rating a house-heating boiler proposed by the authors seems to leave out a most important factor of such a rating, namely the grate surface, or the amount of coal that should be burned per square foot of grate surface.

The authors say, "The capacity or commercial rating of a heating boiler has always been given in terms of the direct radiating surface which it would serve." The capacity of such a boiler thus defined, that is, the amount of radiating surface which it will serve, is an exceedingly variable quantity, depending chiefly upon the amount of coal that is burned under it per hour, which in turn depends on the size of the grate and the rate of combustion. A certain boiler with 1 sq. ft. of grate and say 20 sq. ft. of heating surface may supply 150, 300 or 450 ft. of heating surface, depending on whether the coal is burned at the rate of 4, 8 or 12 lbs. per sq. ft. per hour. It is evident then that no satisfactory rating of a house-heating boiler can be made that does not take into consideration the rate at which the coal is burned. I therefore

would amend the authors' definition of a unit for stating the capacity of a heating boiler so as to make it read as follows:

The foot of radiation shall be 4 lb. of steam per hour condensed at 212° F., and discharged as water at 182° (equivalent to 250 B.T.U. per hour) when the coal is burned at the rate of 4 lbs. per sq. ft. of grate surface per hour.

S. B. FLAGG AND R. L. BEERS. The writers have been engaged during the past two years in planning and carrying on an extended series of tests which the Bureau of Mines is conducting for one of the Government departments. The principal purpose of these tests has been to obtain information as to the relative value for domestic heating purposes of a large number of fucls used by this department, including a number of Canadian and foreign coals. At the same time a comparison is being made of steam and hotwater boilers.

In the development of plans for the tests which the Bureau is now conducting the following considerations governed:

The average residence-heating boiler operates during the most of the heating season at a load less than 40% of its rating. Results were desired showing the comparative values of the fuels under average load conditions, and the tests were therefore run at approximately this load.

Conditions of attention were to be comparable to those in actual service so far as possible. For this reason with most fuels charges of relatively large size were fired so as to give a firing period ranging from 6 to 12 hours.

In the case of the steam boiler installed in a residence, neither the rate of delivery of steam nor that at which the condensation returns is uniform. The boiler output was therefore allowed to vary, but the valve controlling the delivery was so set that with automatic damper regulation an average load of approximately 40% of rating was maintained. This corresponds with the authors' requirement.

So far as possible the test data were mechanically recorded and some of the data so recorded by a second piece of equipment.

In order to reduce errors of starting and stopping the duration of the tests was made approximately 48 hours.

Measurement of output can readily be made in either of two ways. One way is to send the steam delivered by the boiler through a closed-type feedwater heater, the condensing water circulating in the coil, and measure the condensate. The other way, which would obviate the use of calorimeter readings in computing results, is to measure the quantity and rise in temperature of the condensing water, the condensate returning to the boiler.

Selection of equipment for either method may be made from a wide variety, and nearly any desired degree of accuracy obtained in measuring the output.

ROY E. LYND. There are two points in this paper which I would like to discuss. The first is that the titles of the paper and of the proposed testing code both confine themselves to house-heating boilers, and the paper states that the class of boilers indicated by the authors under this heading includes only boilers designed to serve 2,000 ft. of radiation or less. It seems that we make a mistake in thus limiting this code. The same boilers which we use in our houses are used very extensively to heat schools, churches, and other large buildings, and several makes of low-pressure cast-iron sectional boilers are designed to serve as much as 10,000 sq. ft. of radiation. We would do well to eliminate the term house-heating boilers from the title, the paper and the code, and substitute therefor low-pressure heating boilers; and include all low-pressure heating boilers instead of those only which are designed to serve 2,000 ft. of radiation or less. The larger boilers of this class are covered by section (9) of the code, which states that the test conditions should be as nearly as possible like the ordinary operating conditions for the boiler to be tested.

In the A.S.M.E. Boiler Code of 1914, boilers are divided into two classes,-Power Boilers, Section 1, and Boilers used exclusively for Low-Pressure Steam and Hot-Water Heating and Hot-Water Supply, Section 2. This division should be borne in mind in any new testing code. As the proposed testing code is essentially a code for evaporative tests, we are not concerned with boilers for hot-water heating and hot-water supply. It would seem therefore that the new code should cover all boilers used exclusively for low-pressure steam heating, and should be so entitled. The A.S.M.E. Boiler Code, in Section 2, does not limit low-pressure heating boilers to 2,000 ft. or less, and we should not so restrict the testing code.

The second point is in regard to the definition given for a foot of radiation. The authors seem to think that the amount of steam condensed per foot of radiation enters more largely into ordinary heating calculations than the B.T.U. They have assumed a convenient average amount of steam per foot of radiation, and have then converted this into an awkward B.T.U. value. This, to my mind, is wrong. We figure practically everything in connection with heating installations in B.T.U., and it is very rare that the question of the amount of steam involved is raised. I would suggest that the foot of radiation be defined as a transfer of heat equal to 250 B.T.U. per hour. This figure, and its recipro

cal, 0.004, are both very convenient, and would be far preferable to the figures given by the authors.

It has been the writer's practice to test lowpressure boilers at atmospheric pressure, keeping a record of the steam temperature as indicated by a mercury thermometer placed in an oil well directly in the steam chamber in the top of the boiler. The pressures at which these boilers are operated are as a rule so nearly atmospheric, if the heating system is conservatively designed, that a test made at atmospheric pressure comes about as close to actual operating conditions as it can be got. The great advantage of the atmospheric pressure test is, of course, its simplicity, it being unnecessary to use the reducing valve, receiver, and bank of valves spoken of by the authors.

One of the functions performed by this system of pressure control suggested by the authors is in the determination of the time of starting and stopping the test. The test is started by establishing normal running conditions with a pressure of, say, 5 lbs. on the boiler. Then the fire is cleaned and thinned until the pressure drops to say, 3 lbs., when the test is assumed to start. The same conditions are reproduced at the end of the test, the test being over when the pressure drops to the same 3 lbs. This would all be out of the question with a test made at atmospheric pressure. The writer has used for some time a system which is very similar, and which gives practically the same accuracy, and which is applicable to tests made at atmospheric or any higher pressure. Normal running con

ditions are established before the test, and then the fire is cleaned and thinned just as outlined in the paper, but instead of depending on the pressure dropping to a certain starting pressure, the temperature of the flue gases is used as an index. When the temperature of the flue gases falls to a predetermined point, the test is assumed to be started, and at the close of the test the starting conditions are reproduced until the flue-gas temperature taken at the same point in the flue falls to the starting temperature. This method seems preferable, as the flue-gas temperature is more intimately connected with the condition of the fire than the steam pressure is, and at the same time it enables us to use the very much simpler atmospheric pressure conditions.

It has also been the writer's practice, for some time past, to keep accurate records of the draft in the flue, in the firebox, and in the ashpit, by means of differential draft gages. These data sometimes indicate differences in the draft conditions which may explain differences in test results.

MAX FRIEDLANDER. Below is a description of a new method for the continuous determination of the heat balance of house-heating boilers. The principle of the method was suggested by Prof. H. Junkers, the originator of the Junkers calorimeter, and the method was tried out and applied by the writer in a series of actual tests on a steam-heating boiler in 1911 when he was his assistant at the Technical College of Aix-la-Chapelle, Germany.

The idea was to measure all items of a complete heat balance in a continuous way during operation, and for this purpose the boiler was suspended upon a sensitive balance, so the smallest amount of fuel burned off in the boiler could be weighed very exactly at shortest intervals, thus giving a continuous determination of the fuel consumption and the incoming heat. The arrangement is shown in Fig. 1.

The entire steam generated was condensed in a condenser and the condensed water carried back to the boiler. In this way the useful heat could be determined continuously by continuously measuring with a Poncelet vessel the quantity of cooling water used in the condenser and, with the thermometers, the increase in its temperature.

The flue gases were drawn out by a ventilator and carried through a flue-gas calorimeter, in which their entire sensible heat was determined by cooling them down to the room temperature by a water jacket, the quantity of cooling water being measured continuously with a Poncelet vessel, and its rise in temperature also being measured. The volume of the flue gases was recorded with a gas meter of 1,500 liters capacity per revolution.

A quite novel feature was the continuous determination of the loss of heat due to incomplete combustion by a new calorimetric method in which the heat value of the flue gases was measured in a calorimeter fitted with a specially designed burner for which a patent is pending. This method for the calorimetry of flue gases has been developed by the writer in separate experiments and tried out in a great number of actual tests and applications on boilers and combustion engines, and it has been described in detail in a dissertation (not yet published), where all these experiments and tests are also reported. The arrangement for this is also shown in the illustration.

The heat loss due to incomplete combustion was very variable and, with the boiler mentioned, wavered between 8% and 23% of the incoming heat when the operation and combustion was normal, and increased to over 45% when the boiler was operated with insufficient excess of air or otherwise in bad condition. In all cases, however, the heat value of the flue gases decreased continuously, or, in other words, the combustion improved steadily in the proportion as the layer of coal was burning off, thus indicating that the boiler was working in the beginning like a gas producer.

Heat radiation and conduction was determined by temperature measurements of the outer surface of the boiler and its surroundings, and by use of individual co-efficients of heat transfer.

New York Chapter Hears a New Definition of Ventilation.

Members and guests of the New York Chapter who attended the February meeting at the Building Trades Club, February 19, were given a treat in the form of two addresses, one on "Deheating Factors of the Atmosphere and Their Measurement," by George T. Palmer, chief of investigating staff of the New York State Commission on Ventilation; and one on "Physiology of Respiration," by Dr. Milton W. Franklin. Both speakers presented their subjects in a manner that held the close attention of the members for over two hours. The meeting was in charge of a committee headed by J. Irvine Lyle, president of the society.

Mr. Palmer, the first speaker, began by offering a substitute title for his address in the form of "Measurement Without the Use of a Yardstick." After referring generally to the work of the New York State Commission, Mr. Palmer said that there are three principal factors we have to deal with in ventilation work, namely, the thermal factor, the gaseous factor and the floating solids factor. Of these, he said, the thermal factor is the most influential because this affects the body and has to do with the method by which the body loses heat. He described the body as a heat-producing engine whose loss of heat is variable, but whose temperature remains practically the same under all conditions. If a fan blows on a thermometer, he said, the mercury does not fall, yet we feel cooler in a room with a fan running, even though the room temperature may be 68° F.

The thermometer, therefore, does not give all the necessary information. We must know about the evaporative quality of the air. As is well known, the pressure of the moisture in a cloth causes evaporation, and in a study of evaporation it will be found that there is a moisture gradient from the wet bulb thermometer to the surrounding air, or, speaking electrically, there is a difference in potential, the air immediately surrounding the wet bulb being more moist than that a little farther away, and so on. It must also be considered that we do not get the rate of evaporation by use of the sling psychrometer.

Mr. Palmer then described a device that was in use for obtaining the quantity of moisture. This is called an atmometer and includes a porus cup fitted with a U-tube. This instrument, however, applies only to objects at the temperature of the air. It must be remembered that in ventilating work

The body, said Mr. Palmer, can also alter its rate of heat loss which adds to the complications.

The speaker gave one plausible reason why outdoor air seems better than indoor air. Out-of-doors, he said, the body meets a fluctuating air movement, but indoors there is usually a steady, unrelenting air movement which affects the body unfavorably. The vaso-motor system may break down under a steady current of air.

Another point that has to be considered when a wet bulb thermometer is used is that the body is not wet or unclothed. Moreover it does not lose all of its heat through the surface but some is lost through the lungs.

In conclusion Mr. Palmer said the engineer must realize all these facts. He is apt to look too much towards achieving mechanical efficiency and not give enough thought to the comfort of the occupants. These two points do not always coincide. The speaker proposed a new definition of ventilation in place of the old one of maintaining a certain standard of air purity. The new definition as proposed is "the adjustment of the air environment to meet the requirements of comfort, health and efficiency."

He added that the work of the commission will probably continue another year before its final recommendations are given out. At that time, however, the commission proposes

THE ATMOMETER, FOR MEASURING THE DRYING POWER OF THE ATMOSPHERE.

Principal element consists of finger-shaped porous cup, attached to a glass U-tube.

we are dealing with human bodies at a constant temperature of nearly 99° F.

Mr. Palmer described the katathermometer, designed by Leonard Hill (first described in THE HEATING AND VENTILATING MAGAZINE for September, 1915).

A new instrument known as the comfortimeter and designed by Prof. Phelps, was then described by the speaker. This instrument measures the deheating effect of the surrounding atmosphere. In its construction heat is supplied by means of electric resistance coils to a mercury bulb, the bulb becoming heated to above the atmosphere. With the supply of heat constant the bulb is surrounded by a wet cloth and it will then give the amount of heat lost by the air. It is also made up as a recording instrument.

Even with these instruments, said Mr. Palmer, the records obtained do not show what is happening at the feet, but only at the breathing level where they are usually located. The body is something more than a hot object and it is necessary to consider the extremities as well as the main portions.