rE ] NEWCOMBE—KLINOSTATS AND CENT RIFUGES 429 
Lhe motors.—Instead of temporizing with cheap motors, it is 
better to purchase those of known efficiency at the outset. A one- 
fourth horse-power will do the work well. A constant water pressure 
ora constant electric current will demand only one motor. Neither 
of these sources of power being always constant at this university, I 
had to purchase both kinds of motors. ‘The water motor is a Pelton 
t HP with a water head of about 10™. The electric is a Sprague- 
Lundell pattern, + HP. Both motors have a speed of 1,600 revolu- 
tions per minute. 
- 2.—Two klinostats (a and 5), the worm gear (c), and the electric motor 
the worm gear. 
Fic 
back of 
The worm gear (fig. 3, a).—As made by MILLER this reducing 
sear is manufactured in two sizes. In the smaller size the pulley 
Worked by the worm has too teeth, thus reducing the speed to 0.01; 
i the larger size the pulley has 200 teeth, thus reducing to 0.005. 
Besides this reduction caused by the worm, the pulley attached to the 
Worm Shaft and receiving the belt from the motor is four times the 
diameter of the pulley of the motor shaft. Thus the total reduction 
Y the worm gear brings the 1,600 revolutions of the motor down to 
four times or two times per minute, according to the use of the pulley 
mith the 109 teeth or 200 teeth. A revolution of four times per minute 
48 been shown by CzapEx‘ to bring in centrifugal action unless the 
Plant is kept within s°™ of the axis of revolution; and hence, for 
merely Neutralizing the effect of gravitation, one should still further 
* Czapex, Untersuchungen iiber Geotropismus. Jahrb. Wiss. Bot. 27:243. 1895. 
