70 LOVE S MEINIE. 



You will, however, find the book full of im- 

 portant observations, and illustrated by valu- 

 able drawings. But the point in question you 

 must settle for yourselves, and you easily 

 may. Some of you perhaps, knew, in your 

 time, better than the doctor, how a kite 

 stopped ; but I do not doubt that a great many 

 of you also know, now, what is much more 



a propelling power, and so contributing to horizontal 

 motion." 



I will collect these seven reasons for the forward motion, 

 in the gist of them, which I have marked by italics, that the 

 reader may better judge of their collective value. The bird 

 is carried forward, according to Dr. Pettigrew — 



1. Because its wings leap forward. 



2. Because its body has a tendency to swing forward. 



3. Because its wings are screws so constructed as to screw 



upwards and onwards any body suspended from 

 them. 



4. Because the air reacts on the under surfaces of the 



wings. 



5. Because the wings are urged with ever-varying power. 



6. Because the voluntary muscles contract. 



7. Because the bird is heavy. 



What must be the general conditions of modern science, 

 when it is possible for a man of great experimental know- 

 ledge and practical ingenuity, to publish nonsense such as 

 this, becoming, to all intents and purposes, insane, in the 

 passion of his endeavour to overthrow the statements of his 

 rival? Had he merely taken patience to consult any ele- 

 mentary scholar in dynamics, he would have been enabled 

 to understand his own machines, and develope, with credit to 

 himself, what had been rightly judged or noticed by others. 



