BELDT'S AQUARIUM, ST. LOUIS, MISSOURI 
25 
WATCHMAN THERMOSTATS 
These automatic heat regulators will maintain a range of 
proper temperatures for tropical aquariums and are set for about 
75 F. Nos. 1 and 2 are fitted with pure silver contact points. 
All of these thermostats are fitted with hangers and water-proof 
extension cords. 
No. 1—500-watt capacity, complete with outside control knob, will 
not interfere with radios. Has three-way plug attachment so 
that three heaters may be hooked to this one regulator. 
Size of glass tube, 8x1 inches. 
Price $3.75 
No. 2—400-watt capacity with inside regulator, also has three-way 
plug attachment so that three heaters may be used with this 
regulator. The glass tube has an overall length of 8 inches. 
Price $1.85 
No. 3—100-watt thermostat is designed for single heater units for 
aquariums up to 30-gallon capacity; the heat regulator is on 
the inside; the glass tube is 6 inches long. Price $1.00 
Notice 
When adjusting these thermostats, a fraction turn to the right 
increases the temperature and to the left lowers the temperature. 
Seafoam Air Releasers 
Watchman Thermostats 
SEA FOAM AIR RELEASERS 
Each 
Dozen 
No. 
1—1 3 /s 
" round airstone 
$1.50 
$15.00 
No. 
2—1" 
round airstone 
1.35 
13.50 
No. 
3—1" 
square airstone 
1.35 
13.50 
No. 
4—1% 
" diam. by 1V4" cone shape 
1.50 
15.00 
Nos. 1, 2, 3 and 4 airstones are mounted on chromium 
plated fittings. The chromium plated brass tubing has a 
040x3/16" wall and an overall length of 16 inches. 
No. 5—Ornamental diver with air release in helmet, an 
attractive novelty. Each $1.00 
No. 6—Airstone with fitting for rubber tubing. 
Each $0.20 Dozen $2.00 
No. 7—Needle valve for adjusting airflow in each out¬ 
let, also has tees for continued line. 
Each $0.40 Dozen $4.00 
No. 8—Tee pieces for branch connections. 
Each $0.15 Dozen $1.50 
No. 9—Adjustable metal air release for rubber tube con¬ 
nection. Each $0.35 Dozen $3.50 
No. 10—Rubber tubing for airlines from pump to outlets. 
Very durable and will last for years. Prices: 
3 ft. $0.10 50 ft. $1.50 100 ft. $2.75 
No. 11—U channel black rubber for fastening to the ends 
of glass partitions, will fit glass from single win¬ 
dow thickness up to 3/16" plate glass. With the 
aid of these U channel partitions may be made 
tight without danger of breakage. 
Price—Per foot $0.10 5 feet $0.35 
