Notices respecting New Books. 223 



same species : and in support of this opinion, I find that a 

 rhomboid measuring very nearly the same angle as the acute 

 rhomboid of Crichtonite may be derived from the primitive 

 adopted for Mohsite by the simple law ei. But however, it may 

 be observed, that a rhomboid so acute as that of Crichtonite 

 may be derived by simple laws, from many rhomboids ; — thus, 

 for instance, that rhomboid is derivable by a still simpler law e§ 

 from the primitive form of specular iron, or of axotomous iron. 

 Besides, Crichtonite presents a cleavage in a direction perpen- 

 dicular to the axis, and is not sufficiently hard to scratch glass, 

 — two characters which differ from those of Mohsite. 



XLVII. Notices respecting New Books. 



An Historical and Descriptive Account of the Steam-Engine, com- 

 prising a General Vieio of the various Modes of employing Elastic 

 Vapour as a prime Mover in Mechanics : with an Appendix of 

 Patents and Parliamentary Papers connected with the Subject. By 

 C. F. Partington, of the London Institution. Second Edition, 

 Corrected and Enlarged. London, 1826. 8vo. pp. 300. Plates 

 and Diagrams 33. 



THE merits of Mr. Partington's treatise on the steam-engine have 

 been already so well appretiated by the public, that on the 

 present occasion we need only point out the improvements it has 

 received in this second edition. The only additional section it con- 

 tains is an article on steam-boats, from the pen of Mr. Tredgold, 

 furnishing some important mathematical data for the construction 

 of the paddle-wheels ; but several useful tables, and a variety of par- 

 ticulars respecting the progressive improvement and present state 

 of the steam-engine in its different forms, have been incorporated in 

 their proper places. A number of engravings on wood have also 

 been added, representing on an enlarged scale some of the most im- 

 portant parts of the steam-engine, &c. ; together with a quarto plate 

 of a locomotive engine and sections of a steam-vessel. Some less 

 important or redundant statements in the former edition have been 

 omitted ; and the entire work, we think, has been rendered more 

 useful than before. 



Geological and Historical Observations on the Eastern Valleys of 

 Norfolk: By J. W. Robbeuds, jun. 

 Tliis interesting tract furnishes a pleasing instance how much as- 

 sistance may be obtained, from studies which have apparently no mu- 

 tual connexion, in the investigation of any branch of knowledge or 

 subject of inquiry. Mr. llobberds has been led by an examination of 

 the district which has been the object of his attention, to dispute 

 the conclusion of Cuvier, De Luc, and others, that no alteration in 

 the height of the waters of the ocean has taken place for many ages. 

 " If," tiays the latter, *' tlie depression of the level of these seas were 



a matter 



