Page:The American Boy's Handy Book edition 1.djvu/175

the paper, and away will sail the balloon upon its airy voyage.

Never attempt to send up a balloon upon a windy day, for the wind will be sure, sooner or later, to blow the blaze aside and set the paper on fire, and if once it catches up in the air there is not much use in trying to save it.

After you have made a balloon like the one just described and sent it up successfully, you can try other shapes. A very good plan in experimenting is to make a small working model Image missingFig. 101.Method of pasting Paper and Strings for Parachute. of light tissue-paper, fill it with cold air by means of an ordinary fan, and when it is expanded any defect in form or proportion can be readily detected and remedied. If it be too narrow, cut it open at one seam and put in another gore, or vice versâ, until you are satisfied with the result; with this as a pattern, construct your larger balloon. Such a model, eighteen inches high, lies upon the writer's table. He has sent it up in the house several times by holding it a few moments over a burning gas-jet. The balloon rapidly fills with heated air, and when freed soars up to the ceiling, where it rolls along until the air cools, then falls gently to the floor.

The parachute shown in the tail-piece is simply a square piece of paper with a string at each of the four corners, meeting a short distance underneath, where a weight is attached. Fig. 101 shows how to make one that will not tear. It is made of two square pieces of paper. Two pieces of string are laid diagonally across the first paper; on top of this the second piece of