snap coupling that fastens with a catch, needing no screw. The representative firemen of this country have tried for many years Fig. 18.—Perfection Nozzle-Holder. to adopt a universal coupling, as a difference in screw threads often causes serious delays. Owing to the enormous expense that would be incurred in changing every department to one standard, the efforts in that direction have so far been unsuccessful.

The Siamese coupling is a very simple contrivance that has one large opening on one side, and two, three, or four smaller openings on the other. By use of this, several fire streams can be converted into one powerful body of water. In some cases these couplings are provided with valves so that one or more of the different lines of hose can be shut off if necessary. The Siamese coupling has been referred to in connection with the Champion water tower. A reducing coupling is also made by which a hose of large diameter can be coupled to a smaller line, and thus prevent water damage at an incipient fire.

Hose nozzles have been varied to suit about every requirement of the firemen. The outlets of the ordinary nozzles vary, being in some cases a smooth bore, and in others lessened in size by a ring. Fig. 19.—Section of Nozzle showing Ring. The larger nozzles are sometimes provided with an inner tube that will make a division in the stream, and therefore tend to close the stream on itself and prevent spraying. In some cases the nozzle is divided into sections to destroy the revolving motion of the stream, and one nozzle is made with a small hollow tube in the center. The stream having an air space, closes upon it and hangs together for a longer time. The solid body of the noz-