INSTRUCTIONS FOR MAKING PILOT BALLOON OBSERVATIONS 23 



Figure 10.— Inflation balance used for "definite" Inflation (C, three-way stopcock: L, hydrogen 

 line; A'', filler nozzle; V, small rubber tube; W, counterweight). 



additional inflation nozzle to fit the neck of the larger balloons and 

 another brass weight corresponding to the free lift desired. 



63. Use of inflation balance. — After the rider is set on zero of the 

 lower scale and the counterweight removed from the balance pan, the 

 balance should be adjusted to equihbrium. The balloon is now folded 

 to exclude the air and fastened to the nozzle on the balance pan by 

 means of two or three No. 18 rubber bands. It is now carefully 

 weighted in the usual manner on the lower scale by moving the rider 

 to the right. The rider is now set on the upper scale on the number 

 representing the weight of the balloon. The counterweight is placed 

 on the pan beneath the balloon and the inflation is begun by first 

 opening the valve of the hydrogen cylinder, care being taken that the 

 regulator valve is closed, and then by slowly opening the regulator 

 valve. The balloon should not be inflated too rapidly as many burst- 

 ings during inflation are due to too rapid filling. When equilibrium 

 is reached the flow of gas is stopped by closing the regulator valve. 

 The cylinder valve should then be closed to relieve the pressure from 

 the regulator diaphram. The balloon is now removed from the 

 nozzle by holding the neck on the nozzle firmly with one hand while 

 the balloon is lifted slightly and turned a few times with the other 



