12 PRELIMINARY INQUIRIES. 



general principles of my tlieoiy. As to the uniformity of fauna in ancient times, every one knows 

 how complete that was. The same fossils in the older rocks indicate with perfect certainty each for- 

 mation in whatever quarter of the globe it may be ; and the great breaks or commencement of 

 a new phase of life at the end of the palaeozoic and raesozoic of)ochs may be due to some cosmical 

 change having taken place, affecting the conditions of life over the whole globe, at these dates. 



Dr. Babbage's machine furnishes an illustration of the mode in which Nature's action may 

 perhaps be regidated in thus developing sjDecies. Dr. Babbage, as all the world knows, has 

 invented a calculating and an analytical machine. The first is merely a machine for arithmetical 

 calculation, the latter is a contrivance of a much higher and more difficult character. It not only does 

 the arithmetical calculations, but changes the formulae where it is necessary to do so in order to 

 work out the result, and goes through the oj)eration of equation. This machine can put upon paper 

 a series of terms or arithmetical numbers of any kind whatever, following any desii-ed law. If, 

 for example, an order is given to it to make the scries of the natural numbers, 12 3 4, &c., and this 

 order a/oiie is given, it v,-ill go on producing the series of natural numbers, without variation, until 

 the machine is worn out, or the motive power ceases. The parallel to this in our subject would be a 

 law in nature providing for the continuance of siDecies by generation, but providing for no develop- 

 ment of any new form. 



But at the original setting of the machine an order might have been given to it to violate 

 the above law, and at some term millions upon millions of times distant, to substitute a diffijrent 

 number following some other law, and this new law might have been directed to be observed for one 

 turn of the machine, or for any number of turns, and then that the original law should be restored 

 for the future. This woidd not exactlj- be the parallel to the law ordaining the development of new 

 species on the occurrence of any change in condition. It is only a parallel to one producing a new 

 form or species at some certain time, and that time, fixed and independent of the occurrence or 

 concurrence of circumstances. The parallel, to bo complete, would require that the new law should 

 not take place at a fixed predetermined time, but^be dependent on circmnstances, or a cii'cmnstance 

 (as, for example, the occurrence in plants or animals of some change, in the physical condition of 

 themselves or their place of abode.) 



Not being quite satisfied, therefore, with the parallel so far as I could work it out from the 

 account of Dr. Babbage's machine given in any books about it to which I had access, I had recourse to 

 the Doctor himself — to whom I owe many acknowledgments for his kindness and patience with my 

 dullness— and asked him the question whether he could so set the machine that it should go on pro- 

 ducing a series of numbers until a certain concurrence of circumstances should take place, the time 

 when sucli concurrence would or could take place not being known to him, and that then, and not until 

 then, the alteration on the law should take place. The Doctor thought for a moment and then replied, 

 " Certainly I can. I can give the machine an order to go on producing a series of numbers until the 

 last, and the third last, and the fifth last, or any other combination, shall all be the same figure, or 

 shall be some combination of figures — all threes, for example, or all fives, or two fours and one five, 

 and then the new law shall come into operation. I cannot tell, when that may happen, and do 

 not know whether it may ever luqjpen, but whenever it does happen, be it soon or be it late, the 

 new law will immediately come into operation." That is the parallel to our ease, and I use it for 

 the purpose of making more plain to the reader tlie form in which the subject of which 1 have 

 been speaking presents itself to mv mind. 



