EXERCISES. 17 



other authorities, or from your own experience or that of 

 friends, examples of the successful or unsuccessful search 

 for coal. 



6. Instance the advantage of an acquaintance with geology, 

 as regards civil engineering, in the construction of canals, 

 railways, and lines of common road. 



7. Study its connexion with agriculture, in the three par- 

 ticulars here mentioned improvement of soils, drainage, and 

 supply of water, and note local instances of these relations. 



8. Inspect the stone buildings in your neighbourhood, 

 especially those of ancient date ; observe their north and 

 north-western sides, and the comparative resistance which 

 these have offered to the action of the weather. Remark 

 whether the stones are placed in the horizontal position 

 which they occupied in the quarry, like a book laid on its 

 side ; or whether their position be vertical, like one placed 

 on its edge : and 'if the latter, observe if the laminae, or thin 

 flakes of the stone, have not peeled oif, and the stone 

 decayed in consequence. Ascertain the quarries from which 

 the material has been obtained, and the geological formation 

 of their localities. 



9. Collect examples, which are numerous, in the history of 

 the art, of statues, busts, &c., which have but imperfectly 

 withstood the action of time in consequence of the bad 

 quality of the material. 



10. The practice of transferring -to a common-place book 

 any facts of general interest, will speedily enable the 

 student to form a copious and highly valuable store of 

 information. 



