532 SCIENCE PROGRESS. 



Subsequently he sold the machine to an acrobat, who 

 used it for exhibiting purposes with success. 



In 1709, Barthelemy Louren^o, a Portuguese, designed 

 a flying machine, of which illustrations occur in old books. 

 In appearance it was somewhat bird-like, and at either end 

 were two spheres supposed to contain some sort of magic 

 substance, probably either electricity or magnetism, which 

 he imagined endowed with the power of lifting the machine 

 into the air. In addition to these spheres there were a large 

 number of funnels hanging from the top, which upon a 

 windy day would conduct the wind to the under side of 

 an awning and make it act as a sail. If the wind was 

 not blowing, you used a pair of bellows instead, and a man 

 is represented doing this in the figures given in old books, 

 Barthelemy Louren90 wrote to the King of Portugal and 

 submitted the design, asking the King to grant him the sole 

 monopoly of making the machine. The King of Portugal 

 replied that the request was far too modest, and that, in 

 consideration of this wonderful discovery, he appointed 

 Louren^o Professor of Mathematics at the University of 

 Coimbra, at a salary of ^3750 a year in French gold. In 

 spite of the royal decree, however, the machine was, of 

 course, never constructed. 



An attempt was made in 1742, by the Marquis de 

 Bacqueville to cross the Seine with wings, but un- 

 fortunately he broke his leg in addition, and the Histoire 

 des Ballons relates that the experiment produced no further 

 results. 



Up to this point, it will be noticed, all attempts at aerial 

 navigation had led to negative results. A great advance 

 was made in 1783 by Montgollier's discovery of the balloon, 

 which opened up a new and highly promising field for re- 

 search. Henceforth, aeronauts in France became divided 

 into two sections, the plus leger party who sought to 

 navigate the air by balloons, and the plus lourd who 

 endeavoured to construct a machine which though heavier 

 than air would lift itself after the manner of birds and flying 

 animals. It was natural that the plus leger party should 

 for many years hold the field, and we find from the close of 



