vantage. There are also outlets in each room in the second story.

As installed the apparatus is capable of reducing the room temperature from 10° to 15° below the outside, which, with the low dew point, makes a very agreeable atmosphere. The complete absence of any odors was one of the most marked benefits secured. The owner is contemplating the installation of an oil engine-driven electric power plant and refrigerating apparatus in the future, which will effectively lower the cost of lighting, ventilating and refrigerating his establishment.

near

Bower Bros. & Co., Philadelphia, were the contractors.

LEGAL DECISIONS

Is There a Standard Temperature for Heating Buildings?

In an action by a lessor for rent, in which the defense was set up of a breach of a covenant to heat the premises, which consisted of offices, an expert witness for the plaintiff was asked these questions: "What is the standard temperature of offices that are required to be heated?" and "What is the standard temperature of office buildings?" The trial court sustained an objection to each, stating "There is no standards." The degree of heat to be furnished was not specified in the lease; but, on appeal, the court held that the only fair construction was that the plaintiff was to furnish sufficient heat for the contemplated use. It would not do to say that any degree of heat would satisfy the requirement of the contract. It would be equally unreasonable to hold that an excessive amount could be demanded by the tenant. There is also a difference in the degree of heat required by different persons to produce comfort, and is the requirement for an office and for premises occupied for other purposes. There must, therefore, be some measure or test to apply to the covenant to determine whether it has been observed. It must be the degree of heat generally recognized and approved by the class of persons engaged in that particular business, or, what is probably the same thing, the amount of heat to make him comfortable, required by the average person occupying such a building for a similar purpose. The witness had testified, but the testimony was stricken out by the trial court, that the standard temperature was about 70° F. There would probably be no dissent from this; and unless the court was to take judicial notice of it, as a matter of general notoriety, the appellate court thought the

answer of the virtues should have been allowed to stand.-Whitney VS. Aronson, (Cal.), 130 Per. 700.

Guaranty for Supplies by CorporationValidity.

A private corporation engaged in the construction of a hotel building made a contract with B., whereby B. agreed to furnish the labor and materials for the installation of a heating plant, etc. The corporation transmitted to a company to whom B. had applied for supplies a letter, signed by the hotel company's president and secretary informing the company to which B. had applied of his being awarded the contract, that he had placed his order for material with that company on terms that he was to pay 60% of the bills on delivery and balance in 60 days, and stating that the writers were prepared to meet such terms with B., so that the company would be perfectly safe in shipping material to him. The company furnished the material on the strength of the letter, and B. failed to make the payment as agreed. In an action against the hotel company it was held that that company having received the benefit of the material furnished by the plaintiff on the faith of the guaranty that the price would be paid by B., and being in a position to protect itself by withholding from B. sufficient to pay the plaintiff's demand, it was estopped, when sued on the guaranty, to claim that it was ultra vires.-KelloggMackay Co. v. Havre Hotel Co., C. C. A., 199 Fed. 727.

Heating Adjoining Houses-Covenant by

Tenant.

The owner of two adjoining houses, heated by a single boiler, the cost being shared equally by the tenants, leased the house with the boiler to a tenant who fully understood the situation and recognized an easement by implied reservation requiring him to do nothing to the disadvantage of the adjoining property. He thereafter disconnected the heating pipes leading to that property because his lease was silent as to heating it. In a suit by the owner it was held that, as he had no adequate remedy at law, equity would furnish a remedy by injunction to restrain the defendant from preventing the owner from maintaining a fire in the boiler. The tenant was required by his lease to surrender the premises at the end of his term in as good condition as reasonable use and wear would permit, damages by the elements excepted. It was held that he had no right to disconnect and plug up the heating pipes, rendering them useless for the purpose for which they were intended. Smith vs. Taranto, 140 N. Y. Supp. 794.

Plant.

A DISCUSSION.

Interesting comments on the design of the hot water heating system for the sanatorium of the Metropolitan Life Insurance Co., at Mt. McGregor, N. Y. (published in THE HEATING AND VENTILATING MAGAZINE for December and January) are contained in expressions received from correspondents, the principal points of which are given herewith. The author's replies are also presented.

One reference was to the advantages of the one-pipe system for heating buildings located near each other, which were enumerated by the author as including smaller branch mains, less radiator surface, lower friction head and the fact that it may be given a greater reserve capacity for supplying future buildings; also that smaller branch mains are possible with a two-pipe system because there is a greater differential pressure between the flow and return trunk main of the two-pipe system than there is between the two points where the branch mains are taken from the one trunk main. The correspondent states that he has radiators connected on shunt lines, with supply and return on the same system, and uses the same size connections.

Exception was also taken by the correspondent to a statement that radiation will necessarily be larger with a one-pipe system, because the temperature of the water will be lower due to its low velocity through the radiator and to the fact that the same water must pass through one radiator before being reheated.

On these points the author states: "In correctly designed systems the branches are smaller in a two-pipe system than in a shunt system, when operated under like conditions, i. e., with the same differential pressure at the pumps. This is because in a two-pipe system the average pressure producing circulation in the branch mains is somewhat greater than one-half the differential pressure at the pumps, while in a shunt system the average pressure producing circulation in the branch mains is less than the differential pressure at the pumps divided by the number of branch.cs shunted from the main. In other words, the differential pressures on branch mains in a two-pipe system are in parallel, while they are in series in a shunt system. Then with the length of mains and the differential pressures at the pumps remaining the same in each case it is evident that the differential pressure on branch mains will not be affected by the number of branch mains added in a two-pipe system, but will

"Now, with the fact established that there is a greater differential pressure on the branch mains of a two-pipe system, it is obvious that the branch mains must be made larger in the shunt system in order to circulate as much water as the twopipe system. The above conclusion is in strict accord with the best of engineering practice. See N. S. Thompson on "The Equipment of Federal Buildings' (page 250), or Hoffman's Hand Book (page 201) (1910 edition).

"With a large number of branch mains and a small differential pressure, as in the case under consideration, it would not be practical in a shunt system to make the branch mains large enough to supply the same amount of water as is used in the two-pipe system. For this reason a smaller amount of water would be circulated through each building. The temperature of the return water would then necessarily be lower. With the average temperature of the circulating water reduced, it is evident that a greater amount of radiation would be required than is required with the higher water velocity and temperature in the two-pipe system. During the milder winter weather it is often desirable and economical in a hot water system to circulate the water by gravity, as has been done at the Mt. McGregor Sanatorium during the greater part of this winter. To make a shunt system operate by gravity and deliver the same amount of heat under the same conditions, the required radiation near the return end of the line would not only be greater but would be prohibitive, because of the low temperature of the return water."

Another point discussed by our correspondent is the statement that "Although most authorities recommend that the static head on the circulating pumps be kept as low as 100 ft., or 42 lbs., with a differential pressure of 25 to 30 lbs. the circulating pumps have a static head of approximately 160 ft. or 64 lbs. Because of this head the differential pressure caused by friction has been reduced to 17 lbs., making the pressure on the discharge side of the pump 81 lbs." This condition, says our correspondent, would require 34 lbs. of friction head, since the supply pressure is the static plus one-half the pumpage, while the return pressure is the static minus onehalf the pumpage.

The author states that "it is approximately correct to say that the supply pressure is equal to the static pressure, plus

one-half pumpage, when the system is in operation; but this does not take into consideration the additional pressure at starting. To be more accurate, the supply pressure at normal operating conditions is greater than the static plus one-half pump-, age, due to the added friction on this side of the boilers, hot water heater and their connections. The statement referred to may be misleading because of lack of explanation. The pump glands, casings, etc., at starting have a greater pressure on them than at any other time, so in determining the maximum pressure which they must withstand, this pressure was considered. This pressure is the combined pressure of the static head, approximately one-half the friction head, and the additional pressure required to bring the velocity of the water from zero to its normal velocity. As this rate of acceleration can not be definitely ascertained, in my calculations I estimated this required pressure as equal to the friction head on the supply side, thus making the pressure on the discharge side of the pump 81 pounds (64+17), as given."

Regarding the method of connecting the hot water an 1 steam boilers, the point is made by our correspondent that if these boilers are made interchangeable with the piping on high pressure steam or hot water heating, it might be dangerous unless the steam boilers were cut off by a blank flange from the water system. In any case, a live steam heater would cost less than the inter-connecting piping and would give better satisfaction.

On this point the author states:,

"Why the boiler plant as shown is dangerous, I am not able to see. Under normal pressures, gate valves have very little tendency to leak, and when there is the same pressure on each side of the valve there is no possibility of it leaking. Con. trary to what has been said, I believe that the boiler plant as installed is much cheaper than a plant operated by a live steam heater, and is by far more simple to operate. In addition to the apparatus shown, a live steam heating plant would require a large live steam heater, additional boiler feed pumps, a large thermostatic valve and the additional steam piping for this apparatus. As for danger, there is greater danger of a thermostatic valve failing to work than there is of a gate valve failing to hold. In addition, the hot water boilers are more efficient because the comparatively low temperature of the water will reduce the temperature of the flue gases lower tan it is possible for a high pressure boiler to do, thus getting a greater percentage of the heat from the hot gases."

Erratum.

Attention is called to an error that crept into the article, published in the January, 1914, issue, describing the heating equipment of the Mt. McGregor Sanatorium. On page 26, first column, eighth line from the bottom, the statement "values for the drop in pounds per 100 ft." should read "values for the drop in feet per 100 ft." This refers especially to the table (Table 2), giving the average values for pressure drop in flow and return mains.

The author also desires to call attention to an error in the formula given on page 26 of the January issue for loss in friction in feet per 100 feet of flow and return mains. The formula in its corrected form is as follows:

Illinois Chapter on Factory Heating.

"Hot Blast vs. Direct Steam Heating for Factory Purposes" was the subject for debate at the January meeting of the Illinois Chapter and led to an exhaustive discussion of the subject. The meeting was held at the Great Northern Hotel, January 12, with President H. M. Hart in the chair. Previous to the debate of the evening R. M. Stackhouse answered a question which had been deposited in the Question Box, regarding the effect of a long horizontal breeching on the draft of a house heating boiler. He showed how this condition would require a higher stack.

President Hart, on behalf of the Chicago Ventilation Commission, reported that tests had been made on two theatres in Chicago to determine the circulation of the air through them; also, that a test cabinet had been built for the purpose of testing the effects of ventilation and that two tests had been made. President Hart stated that he and Mr. Davis had passed 11⁄2 hours in the sealed cabinet wherein the temperature had gone up and humidity risen to practically the point of saturation.

Mr. Hart asked the question as to "What is the difference in heat transmission between gases in a boiler and steam in a hot water coil?" Mr. Widdicombe and Mr. Hart will answer this question at the next meeting.

Mr. Stannard asked whether there is "any difference in the heat transmission through