Recent editorials in THE JOURNAL pointing out the facts that the streams of water obtained from our Fire Engines are not in proportion to the power exercised by the Engines, nor to the capacity of the hose, seem to have attracted marked attention. The articles have been widely copied in the scientific and specialty papers, and we do not doubt but a train of thought has been aroused that will set our practical Yankees at work to remedy the difficulty. We intimated that, in our judgment, neither the play-pipes nor nozzles in general use were ot a character calculated to secure the best results, and we asked “ who will invent the nozzle of the future?” In response to this inquiry, Andrew J. Morse, of Boston, has written us a letter, not tor publication, containing some hints upon this subject which we shall incorporate in this article. Mr. Morse is a veteran worker in connection with Fire Department suppl es, an inventor of many valuable appliances, and a scientific and conscientious workman in whatever he undertakes to do. He has devised one of the best couplings made, has made various improvements in nozzles and play-pipes, and his latest invention, the “ monitor nozzle,” attracted much attention and received unqualified approbation at its recent exhibition at the Chiefs’ Convention in Boston. A full description of it will be found on page 297 of the current volume of THE JOURNAL. We regret that Mr. Morse did not put his ideas in form for publication.

We have noticed that streams ot water spray and become almost valueless for fire extinguishing purposes very soon after leaving the nozzle, instead of being projected as bodies of solid water. Our - Steamers are capable of furnishing adequate water pressure the 2j4 inch hose carries a liberal supply of water ; play-pipes and nozzles are constructed upon alleged scientific principles; yet the stream delivered at the nozzle is not proportioned to the power exerted to project it. There is considerable loss of power from friction in the hose, but this does not, we believe, account for the inadequate stream delivered. At the end ot the hose is attached a tapering play-pipe, and to this a tapering nozzle, whereby a volume of water 2 1/2 inches in diameter is forced from a nozzle usually 1 1/8 or 1 1/4 inches in diameter. Now, we are of the decided opinion that the faulty construction of the play-pipe and nozzle is responsible, to a large extent, for the insufficient stream delivered. We are aware that scientific Engineers have laid down the rules which govern the construction of play-pipes and nozzles, but, in view ot the fact that this method of construction does not give satisfactory results, would it not be well for some unscientific but thoroughly practical man, to experiment upon methods entirely different from those laid down? Take, in fact, a new departure in the plan of delivering water upon a fire, and see if something better cannot be obtained. The tendency of a stream to spray so soon after leaving the nozzle is owing to a lack of harmony of proportion between the outlet and the supply. This can be demonstrated by using a spray nozzle, which, by closing, diminishes the outlet, thereby increasing the velocity of the stream, and causing it to spray; open the nozzle, thus restoring the outlet to its full capacity, the velocity is decreased, and the stream becomes solid. This is the effect produced by a spray nozzle, and, under the usual conditions of use, all nozzles are, to a certain extent, transformed into spray nozzles. To illustrate this, let us suppose a Steamer at work and forcing a stream as far as it is possible for it to do and retain its solidity ; the distance thrown not being sufficient for the work required, it is usual to call for additional pressure at the Steamer. Additional pressure is put on, more water is forced through the pumps and hose up to the outlet, which not being susceptible of enlargement to accomodate the increased volume of water, an obstruction is presented to the flow of the water, and the nozzle becomes, to a certain extent, a spray nozzle, tearing the stream to pieces, and delivering it in the form of spray. The extent of this spraying is proportionate to the increase of pressure beyond a point that is in harmony with the size of the outlet. A good illustration of the effects of pressure above the capacity of the outlet is to be found in the ordinary soda water fountain. These are ordinarily charged to a pressure of 180 or 200 pounds. When the draft tube is first connected, the stream is forced through the outlet with great violence, causing it to spray into fine particles; repeated drafts reduces the pressure in the tank, causing the water to spray less and less at the outlet, until finally it is delivered in a solid stream, the amount of pressure having been exhausted until it harmonizes with the capacity of the outlet. The condition of the atmosphere has a considerable influence in causing a stream to spray. When the atmosphere is humid, and full of moisture, the water as delivered at the nozzle has a great affinity for the surrounding moisture in the air, and the particles constituting the outer surface of the stream have a tendency to separate from it and mix with those particles with which the air is charged.

If you are a current subscriber, login here to access this content.

If you would like to become a subscriber, please visit us here.