20 BULLETIN 173, U. S. NATIONAL MUSEUM 



needle nozzles that varied the size of the jets (1899-1903), deflecting 

 nozzles (1899), and, finally (1903), the stream deflectors, which deflect 

 the jets independently of the nozzles. Later developments have been 

 in methods of securing automatic control of the wheels and in im- 

 proving designs to facilitate replacements and repairs. 



WATER-MILL GEARING 



Plate 7 



U.S.N.M. nos. 310538 and 310539; originals; gift of Charles H. Estes, photo- 

 graph nos. 31705A and B. 



Two pairs of wooden spur gears and cogwheels from the Estes 

 Mill at Sperryville, Va. Estimated to have been made about 1870; 

 collected in 1932. 



Tlie spur gears (U.S.N.M no. 310538, photograph no. 31705A) are 

 each 24-inch, 38-tooth gears, made up of two solid oak disks held 

 together with iron rods riveted over hand-cut square washers. The 

 teeth are of black locust held between the disks and secured with 

 wooden pegs. (PI. 7, fig. 1.) 



The cogwheels (U.S.N.M. no. 310539, photograph no. 31705B) are 

 a pair of one 18-inch, 20-tooth wheel and one 10-inch, 11-tooth wheel. 

 The disks are red oak, held together with black-locust dowels spread 

 with yellow-pine wedges. The teeth are dogwood, secured by black- 

 locust pegs, which bear on hickory plugs. (PI. 7, fig. 2.) 



DOMESTIC WATER MOTOR, 1878 



U.S.N.M. no. 309203 ; original patent model ; transferred from the United 

 States Patent Office; not illustrated. 



This model was submitted with the application for the patent 

 issued to Jolin Haworth, of Philadelphia, Pa., April 30, 1878, no. 

 203035. 



The model represents a water motor having a vertical cylindrical 

 water chute, within the lower end of which a small parallel-flow 

 reaction turbine wheel is located. The wheel is carried on a shaft 

 that passes through the water chute and a stuffing box at its opposite 

 end to carry a worm gear from which the power of the motor is 

 supplied. The motor is designed to operate a sewing machine, and 

 the drive shaft carries a 2-bladed propeller fan for fanning the 

 machine operator. 



Motors of this type operating from the faucet pressure of city 

 water systems were in use up to a few years ago to drive sewing 

 machines, fans, and washing machines. Their use was discontinued 

 with the development of the small electric motor, cheap electric cur- 

 rent, and the practice of installing individual meters in municipal 

 water systems. 



