AERIAL NAVIGATION. 175 



the speed attained has variously been stated at 8 to IM niile« per hour. 

 Nevertheless the design of Count Zeppelin contained many excellent 

 features, and a movement is now on foot in Germany to enable him to 

 try again, throug'h means of a popular subscription. The mere size, 

 if he builds again as large, is a great element of success, for as the 

 cubic contents and lift increase as the cube of the dimensions, while 

 the weights increase in a far smaller ratio, a l)alloon of this g-reat size 

 ought to be able to lift a very powerful motor, and to attain a speed 

 of 30 or more miles per hour. He has shown that the size is not 

 beyond the possibilit}' of control. 



Meanwhile gasoline motors had been increasing in efficiency and 

 diminishing in weight. The French war department gave no sign and 

 it was reserved for a Brazilian, Mr, Santos Dumont, to show to the 

 Parisians what could l)e accom])lished by equipping an air ship with a 

 gasoline motor. The history of his triumphs is so present to all minds 

 that it need only be alluded to, l)ut it may be interesting to give some 

 details of the sizes and arrangments of his various balloons. His first 

 idea seems to have been that, in order to make it managea))le, a balloon 

 should ])e made as small as possible, and that it was practicable to 

 disencumber it of many adjuncts hitherto considered indispensable. 

 Neglecting- to stud}" carefully what had been found out by his prede- 

 cessors, he had to learn by experience, and he built five balloons, all 

 navigaldes, before he produced, in 1901, his No. 6, with which he won 

 the Deutsch prize b}^ sailing 3i miles and return in half an hour. 

 This balloon was 108 feet long, 20 feet in diameter, and was provided 

 with a gasoline motor of 10 horsepower which might be driven up to 

 18 or 20 horsepower. While the speed over the ground was 11 miles 

 an hour, retarded as it was hy a light Avind, the speed through the air 

 was about 19 miles an hour, a small but marked advance over any 

 previous performance; but the result would have been still better if 

 the shape had been that of Colonel Renard's balloon. 



Since then Mr. Santos Dumont has luiilt four new navigable balloons: 

 His No. 7, with which he expects to compete at St. Louis in 1901, is 

 160 feet long and 23 feet in diameter, and is to be provided with a 

 motor of 60 horsepower; his No. 8, which was sold to parties in New 

 York last year; his No. 9, which is his visiting balloon, being only 50 

 feet long and 18 feet in diameter and provided with a 3-horsepower 

 motor. Its speed is onl}" 10 miles an hour, but it is handy to ride 

 ai"oiuid to breakfast or afternoon teas. He is now finishing his No. 10, 

 the ()nuii])us, which is 157 feet long and 28 feet in diameter, with a 

 motor of 16 horsepower. Fares are to be charged for by the pound 

 of passenger when it comes out next spring. 



Emulators of Santos Dumont there have been that have come to 

 grief. Mr. iioze built in 1901 a catamaran consisting of two twin 

 balloons, which, although 118 feet long, failed to raise their own 



