26 
BELDT'S AQUARIUM, ST. LOUIS, MISSOURI 
WATCHMAN THERMOSTATS 
A special condenser is built in these thermostats to prevent 
radio interference. 
Notice 
When adjusting these thermostats, a fraction turn to the right 
increases the temperature and to the left lowers the temperature. 
Watchman Thermostats 
These thermostats only regulate the temperature and can be 
used with any non thermostatic controlled heater. 
SEA FOAM AIR RELEASERS 
Each Dozen 
No. 1—1 Ys" 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. A — l Vs" diam. by \ 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 $0.25 Dozen $2.50 
No. 7—Needle valve for adjusting airflow in each out¬ 
let, also has tees for continued line. 
Each $0.50 Dozen $5.00 
No. 8—Tee pieces for branch connections. 
Each $0.20 Dozen $2.00 
No. 9—Adjustable metal air release for rubber tube con¬ 
nection. Each $0.40 Dozen $4.00 
No. 10—Rubber tubing for airlines from the airpump to 
outlets. No, 2 grade black. 
3 ft. $0.10 50 ft. $1.50 100 ft. $2.80 
No. 10-A—Best grade rubber tubing. 
3 ft.. $0.15 50 ft. $2.00 100 ft. $3.50 
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 $0.40 
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 .. .$2.25 
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 $1.25 
Seafoam Air Releasers 
