152 



CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. 



F203. 



No. 3000. 



No. 3002. 



No. 3004. 



CLAMP, Stone's Tension, modified form, for use in experiments where it is desired to maintain 

 a strain on a wire or cord and enable an individual operator to readily adjust the tension with- 

 out the co-operation of a second person. 



This clamp is substantially made of cast iron and neatly finished. Will fit any table or board 

 7 centimeters thick or less. Wires, cords, etc., are securely clamped by an eccentric lever, as 

 shown in the illustration $0.50 



2990. CLIPS, Spring, of wood, for holding tubes, etc per dozen .20 



3000. CLOCK, Interval. Alarm may be set to ring at the expiration of any interval from a quarter of 

 a minute up to two hours. Does not start until the alarm is wound, and stops with the ring- 

 ing of the alarm. Valuable in all experiments in which action for a definite length of time is 

 necessary, as the operator is free to go on with other duties without fear of overrunning the 

 time. Many uses of this timer will readily present themselves. Well made and reliable. $4.00 



For TIME SWITCH for use with No. 3000, see No. 13810. 



3002. CLOCK, Laboratory. This is the best clock we can furnish, adapted to the needs of the average 

 laboratory. It is an eight-day Waltham movement, weight-driven clock, and we guarantee it 

 to be a reliable timekeeper. 



The dial is 12 inches in diameter with seconds divisions. It is provided with hour and minute 

 hands and a full sweep seconds hand for timing laboratory experiments. 



The pendulum is full seconds length, and provided with an adjustable platinum contact and a 

 mercury well of improved construction, adjustable from the outside of the case, is mounted in 

 correct position. 



The clock is completely enclosed in a polished oak case, with glass front and glass covered open- 

 ing in the sides opposite the works, and binding posts on the outside for attaching battery 

 and sounder 150.00 



3004. CLOCK, Laboratory. An eight-day clock with good movement, driven by two weights. The 

 dial is 12 inches in diameter and the pendulum beats seconds. The clock is provided with mer- 

 cury contact adjustable from the outside of the case, and with binding posts for electrical con- 

 nections. Complete in polished oak case with glass door 55.00 



3006. 



CLOTH, Tracing, thin, good quality. 



Width, inches 



Per yard 



30 

 .90 



36 

 1.00 



38 

 1.25 



42 

 1.75 



3008. CLOTH, Cotton, Turkey Bed, used to show bleaching effect of chlorine per yard .25 



