REVIEWS. 



hill (when he requires to sink a well for instance), by refe- 

 rence to two pegs on any line in it. 



Mr. Denton recommends this latter system in preference 

 to any other, as he advocates the practical demonstration of 

 the best means of drainage by the submersion of the model 

 in water, and by gradually removing it the subsidence will 

 take place in the same way as in nature ; thus showing the 

 portions which require an improved system, and those to 

 which the surplus of water in other parts might be conveyed 

 with great advantage. 



This is the principle of the model maps, and is well worthy 

 attention. Mr. Denton has included in his work, notices of 

 several new instruments of his invention ; constructed for 

 the purpose of affording a ready index of the respective 

 heights of any two elevations or pieces of ground ; and 

 for the measurement of embankments, cuttings, &c ; but as 

 these do not relate to our subject, we are compelled to refer 

 to them thus briefly. We cannot close our short notice with- 

 out inviting attention to Mr. Denton's beautiful models, 

 which w^e are sure he will feel much pleasure in exhibiting 

 to any of our readers who may feel an interest in the system 

 of model mapping in its various applications. 



Annates des sciences geologiques, ou archives de Geologic, Mi- 

 ner alogie et Paleontologies ^c, ^c, Publiees par M. A, 

 Riviere, 8vo. in monthly parts. Paris, J. B. Bailliere. x 



The first monthly part of this work appeared on the 31st 

 of January last, and, together with the February number, 

 has been forwarded to us. We are glad to find a contem- 

 porary established abroad for the same purposes as our own 

 work, and shall feel pleasure in communicating to our readers 

 such novelties as its pages may aff'ord, and our own will 

 permit. 



