460 



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



No. 12512. 



No. 12538. 



No. 12540. 



No. 12552. 



12502. TUBE BACK for 6 No. 12500 Soil Tubes. The tube rack consists of a cast iron base, smoothly 

 finished and japanned, to which is attached an upright standard. On this standard are car- 

 ried two castings, the lower one being arranged to take and hold the lower ends of the soil 

 tubes by means of lugs on its upper surface, and the upper consisting of a series of rings to 

 support the upper ends of the soil tubes in a concentric position. This arrangement holds the 

 tubes securely, but still allows them to be removed or replaced very easily. At the same timo 



it is compact, the rack and tubes occupying less than one square foot of desk room $2.00 



(For illustration, see page 459.) 



12506. SUPPLY TANK, used in determining the comparative rate of flow of water through various 

 soils. This tank is made of polished brass and rests on the top of the standard of the tube 

 rack by means of a socket in its base. Two short brass tubes extend downward from the base 

 of the tank in such a position as to fall within the two soil tubes on opposite sides of the 

 rack. The six soil tubes having been connected in series, the water flows from the tank to 



the soil tubes, maintaining a constant water level therein 3.50 



(For illustration, see page 459.) 



12508. SOIL TUBE AUGER for removing wet soil from tubes. This auger is 1% inches in diameter, 

 of twist pattern and made from polished cast steel. Will clean tubes to the bottom 2.50 



12512. WATER RETENTION CUP, for determining the maximum water retained by soil. Of brass 

 2 inches in diameter by % inch high, with diaphragm of perforated metal fastened about 

 %6 inch below top. This cup is used in studying the wilting point by means of the direct 

 relationship which exists between the maximum water retained by any soil and the wilting 

 point. (See Hilgard's "Soils," page 209) 30 



1253U. SOLDER, Bar Form, half lead and half tin. Approximate weight, iy Ibs Per bar 1.50 



12532. SOLDER, Wire Form, half lead and half tin Per pound 1.00 



12534. SOLDER, Wire Form, with resin center; half lead and half tin. Used for all electrical joints 

 and splices where danger of corrosion must be eliminated. No flux required when using this 

 solder. In 1-pound packages Per package 1.25 



12538. SOLDERING COPPER, % lb., with handle 60 



12540. SOLDERING COPPERS, Electric, for either A. C. or D. C. circuits. Tip interchangeable and 

 can be replaced instantly. With cord and plug. In ordering please state exact voltage. 



No " A B 



Length, inches 10 14% 



Weight, ounces 9 18 



Diameter of tip, inches % % 



Watts 60 150 



Each 7.50 9.50 



12544. SOLDERING COPPER, Jewelers', 1 ounce, high grade, for instrument use 25 



12548. SOLDERING PASTE, easy to apply, non-acid, fumeless, non-corrosive. Especially useful for 

 electrical work and in out-of-the-way places. In metal cans. 



No A B 



Size, ounces 8 



Each 35 .85 



12552. SOLDERING OUTFIT, consisting of a soldering iron, bar of solder, scraper and flux, in a neat 

 wood box .60 



12554. SOLDERING OUTFIT, less elaborate than No. 12552, consisting of soldering iron, piece of wire 



solder, and flux .25 



SOLDERING IRON HEATER, SOP Burners Nos. 2114-6. 



