282 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 

 SET OF PNEUMATIC APPAKATUS. PRICE $42 00. 



Consisting of a Double-barrel Air-Pump, worked by racks and 

 cog-wheel, by double lever handles, mounted on a polished mahogany 

 frame. Price $23. 



2. Swelled Air-Pump Receiver - - $1 75 



3. Hand and Bladder-Glass - - - - 75 



4. Pressure-Glass 75 



5 Fountain in Vacuo - - .... - 4 00 



6. Bell " and Receiver - - 2 25 



7. Flask, with Stop-Cock, to weigh Air - - 2 00 



8. Freezing Apparatus and Low Receiver - 1 50 



9. Bolt-head Experiment 1 25 



10. Air Shower Experiment - - - - 75 



11. Magdeburg Hemispheres ... 400 



With the above-represented Air-Pump, and ten different appen- 

 dages, many interesting experiments may be performed, and all the 

 most important connected therewith, illustrated in a satisfactory man- 

 ner. All but the last two are drawn in the cut. On the right of the 

 cut is represented a brass Condensing Pump, the barrel ten inches 

 long, and one and a half diameter, and a strong glass Air-Chamber, 

 with cap, stop-cock, and pipes, attached ; also, a Revolving Jet, 

 Straight Jet, and Rose Jet ; the whole being a complete apparatus 

 for the condensation of air and experiments therewith. The jets may 

 be used by the passage of either air or water through them, price $12. 

 An apparatus with cylindrical copper air-chamber, at the same price. 

 Also, a Brass Tube for illustrating the principle of the Air-Gun, price 

 $1 50. The Air-Pump apparatus, or any portion of it, may be used 

 with a Single-Barrel Air-Pump, at $7, $9, or $12, according to size ; 

 or with Pike's Improved Single-Barrel Air-Pump, price $20, being 

 the largest, most powerful, and durable pump made for the price. 



