HISTORY OP AEROSTATION. 65 



Of these, some attempts have been upon meclrauical principles, or 

 by virtue of the powers of mechanism : and such are conceived to 

 be the instances related of (he flying pigeon made by Archjtas ; the 

 flying eagle and fly by Regiomontanus, and various others. Again, 

 other projects have been formed tor attaching wings to some part 

 of the body, which were to be moved either by the hands or feet, 

 by the help of mechanical powers ; so that striking the air with them, 

 after the manner of the wings of a bird, the person might raise him- 

 self in the air, and transport himself through it, in imitation of that 

 animal. The romances of almost every nation have recorded in- 

 stances of persons being carried through the air, both by the agency 

 of spirits and mechanical inventions; but till the time of the cele- 

 brated Lord Bacon, no rational principle appears ever to have been 

 thought of by which this might be accomplished. Friar Bacon, in. 

 deed, had written upon the subject; and many had supposed, that, 

 by means of artificial wings, a man might fly as well as a bird : but 

 these opinions were refuted by Borelli in his treatise De Motu Ani. 

 malium, where, from a comparison between the power of the mus- 

 cles which move the wings of a bird, and those which move the arms 

 of a man, he demonstrates that the latter are utterly insufficient to 

 strike the air with such force as to raise him from the ground. In 

 the year l6f2, Bishop Wilkins published his " Discovery of the 

 New World," in which he certainly seems to have conceived the 

 idea of raising bodies into the atmosphere by filling them with rare- 

 fied air. This, however, he did not by any means pursue ; but 

 rested his hopes upon mechanical motions, to be accomplished by 

 human strength, or by springs, &c. which have been proved inca. 

 pable of answering any useful purpose. The Jesuit, Francis Lann, 

 cotemporary with Bishop Wilkins, proposed to exhaust hollow balls 

 of metal of their air, and by that means occasion them to ascend. 

 But though the theory was unexceptionable, the means were certainly 

 insufficient to the end : for a vessel of cupper, made sufficiently thin 

 to float in the atmosphere, would be utterly unable to resist the ex- 

 ternal pressure, which being demonstrated, no attempt was made 

 upon that principle. So that we may reckon nothing to have been 

 particularly concerted towards aerostation, till the experiment of on 

 Gasman, a Portuguese friar, wlm is reported early in the last century 

 to have launched a paper b-i\: in; ilie aii ; \Oitch, however, soon 

 fell, after attaining the height of 1OO feet. Soon aficr Mr. Caveru 

 dish's discotery of the specific gravity of inflammable air, it occurred 



TOt. VI. V 



