LECTUKE I 



The Cosmogonists First beginnings of accurate and detailed ob- 

 servation regarding the Earth's crust and its history Guettard 

 and his labours. 



IN science, as in all other departments of human know- 

 ledge and inquiry, no thorough grasp of a subject can be 

 gained, unless the history of its development is clearly 

 appreciated. While eagerly pressing forward in the search 

 after the secrets of Nature, we are apt to keep the eye too 

 constantly fixed on the way that has to be travelled, and 

 to lose sight and remembrance of the paths already trodden. 

 Yet it is eminently useful now and then to pause in the 

 race, and to look backward over the ground that has been 

 traversed, to mark the errors as well as the successes of 

 the journey, to note the hindrances and the helps which 

 we and our predecessors have encountered, and to realize 

 what have been the influences that have more especially 

 tended to retard or quicken the progress of research. 



Such a review is an eminently human and instructive 

 exercise. Bringing the lives and deeds of our forerunners 

 vividly before us, it imparts even to the most abstruse 

 and technical subjects much of the personal charm which 



B 



