280 IJEXJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



SET OF APPARATUS FOB MOTION, MECHANICS, AND 

 MATHEMATICS. PRICE $72 00. 



1 . Inertia Apparatus - - - - $1 50 



2. Collision Balls and Frame - - - - 3 00 



3. Apparatus for Impenetrability - - - 1 00 



4. Adhesion Plates - 150 



5. Capillary Tubes 1 00 



6. to 10. Set of Mechanical Powers - - - 16 00 



11. Rocking-Horsc - 075 



12. Planetarium - - - - - 'J r - - 7 50 



13. Centrifugal Machine 4 50 



14. Surveyors' Compasses, 5 inches diameter - 18 00 



15. " Chain, 2 poles - - - - 1 25 



16. Quadrant - > :* - 1500 



17. Hour-Glass - - - .... 125 



The Mechanical Powers, figures 6, 7, 8, 9, and 10, consisting of 

 levers and pulleys, arranged on a mahogany frame, 24 inches long 

 26 inches high, with four systems of pulleys attached. On each side 

 of the frame, behind the pulleys, are graduated scales, with cords pas- 

 sing across the length of the frame and dividing the space into 24 

 equal parts, to show the number of inches, rise and fall, of the 

 weights, and that it is inversely as the power gained. Brass levers 

 on the top of the first, second, and third orders ; bent lever and pulley 

 for passing over the cord ; and on one end is fixed the wheel and 

 axle, with four different diameters. The accompaniments are : A large 

 and well-made inclined plane, with graduated arch and carriage, 

 wedge jointed in two parts, screw and lever, and screw as an inclined 

 plane; and a set of 10 brass weights, from one quarter of an ounce 

 to eight ounces. Price $16 00. Also Larger Sets, at $35 and $60. 

 Atwood Machines, at $25, $40, $100, and $120. Whirling Tables 

 and Apparatus, $30, and $75. 



