22 BENJ. PIKE'S, JR., PRICE CATALOGUE. 



No. 



^479 Fig. 348, stand for the fusion of wire, by the 



electric spark, - $ 3.00 



480 Fig. 349, ignition of charcoal points in chlo- 



rine, - 6.00 



481 Fig. 350, sphere and point, 1.50 



482 Fig. 357, Biot's movable hemispheres and 



ball, - - - 4.50 



483 Fig. 352, Farraday's bent electrical conductor, 1.75 



484 Fig. 352, apparatus to show that extending 



the surface diminishes the quantity of 

 electricity, - - 2.00 



485 Fig. 354, insulated conductor for induction, 



japanned tin, 2.00 



486 Fig. 354, insulated conductor for induction, 



in brass, 3.00 



487 Fig. 355, set of three insulated conductors for 



induction, - : *" $3 to 8.00 



488 Fig. 356, double jar, 3.00 



489 Fig. 357, insulated stand, 2.00 



490 Fig. 358, series of insulated Leyden jars, each 2.25 



491 Fig. 359, Leyden jar, with discharging elec- 



trometer, - - 2.50 



492 Fig. 360, eudiometer for exploding gases by 



electricity, - $2.50 to 4.00 



493 Fig. 361, apparatus for passing an electric 



spark through gases, - - $3 to 6.00 



494 Fig. 362, Kinnersley's electrical air thermo- 



meter, . - 3.00 



495 Fig. 363, Cavallo's rain electroscope, - 2.00 



496 Fig. 364, Cavallo's bottle electroscope, 0.50 



497 Fig. 365, Coulomb's torsian balance, - $10 to 12.00 



498 Fig. 366, dry pile, or electrical chime, - 20.00 



499 Fig. 367, thunder house, - 1.75 



500 Fig. 368, thunder house, with insulated slid- 



ing rod, 4.00 



501 Fig. 369, electrical pyramid, - $2 and 3.00 



502 Fig. 370, platina points for lightning rods, $3 to 4.00 

 -503 Fig. 371, electrical powder house, - 6.00 



504 Ether cup, - - 0.50 



-505 Hydrogen gas generator for charging cannon, &c. 5.00 



506 Fig. 372, medical electrical machine, - $12 to 18.00 



507 Fig. 374, insulating stool, - - - $3 to 4.50 



