Opening Address. 11 



remarkable and perceptible diminution of its orbit, tbat it is 

 moving in a resisting medium, and will eventually fall into the 

 sun. And following up this suggestion of Babbage about the 

 propagation of every uttered whisper, I may mention a remark- 

 able supposition of some modern philosophers, that the image of 

 an object formed upon the retina becomes permanently impressed 

 there, so much so that it is said a murderer has been detected in 

 consequence of his image being found depicted on the retina of 

 the murdered man's eye. 



One more point in the writings of this philosopher, I will refer 

 to with your patience. It has been remarked by atheistical 

 writers, that " Miracles cannot be true, because they are con- 

 trary to experience." But Babbage, who is not only a profound 

 mathematician, but a very practical and liberal philosopher, re- 

 minds us of a remarkable fact, well known to the student of the 

 abstract study of pure mathematics. 



There are a multiplicity of curves, all of which follow some 

 general law dependent upon the principles of geometry or me- 

 chanics. To take some simple instances : — The circle has for its 

 law that every point in it is equally distant from the centre. 

 This is practically evident to anyone who has a pair of compasses. 



Then there is the Ellipse. One of its properties being, that if 

 a continuous string be attached to two fixed points, and a move- 

 able peg made to trace a curve, the string all the time being kept 

 stretched, the two lengths added together will be always the same. 

 It is a curve which most planetary bodies describe. The method 

 is known to most practical gardeners. 



Then there is the Parabola, or the path described by a bullet 

 projected from a rifle. 



And so we might continue. But as we proceed, we arrive at a 

 class of curves as certain in their nature as any that I have re- 

 ferred to, and following as much a general law. But in some of 

 them an apparent paradox occurs. There are certain points 

 called "singular points," which are essentially points in the 

 curve, and yet do not lie in it. They are derived from the same 

 general law, and yet form apparent exceptions. And so Babbage 

 argues, and with good reason, that miracles may be beyond our 

 comprehension ; and although they may be apparently contrary 

 to the general laws of Nature, yet they may be but singular ex- 



