Xudces rcspaiing Xcvj Booh. 451 



also, that unless the tlislances were withni certain limits 

 the precedhig limb of the moon would not be so proper as 

 ihe centre, on account of the change in the moon's diameter. 

 But this would not be necessary for experiments within the 

 shores of our island. Should any gentlemen, in various parts 

 of the country, be desirous of making observations of this 

 kind, the writer would with pleasure prepare a table of the 

 moon's place corrected, and a few selected stars preceding and 

 following of the same declination, as near as possible, for the 

 early age of the moon, durmg the beginning of the next year, 

 and transmit it to the Philosophical Magazine. The result 

 of such observations would ascertain to v/hat degree of accu- 

 racy this method would answer the purpose intended. But 

 the observed time at Greenwich is the great desideratum, as a 

 guide to all observers, m a series of experiments of this 

 nature. jVI. 



Dec. 9, 1823. 



XCIV. Notices respectitig New Books. 



\ SECOND edition of Mr. Tredgold's Essay on the Strength 

 ^ of Cast Iron is just published; with considerable additions. 

 These additions consist in popular illustrations and examples of 

 the rules; a great variety of new expei'iments on cast iron, from 

 whence the delation between the quality and the appearance of 

 the fracture has been ascertained, and the qualities of iron fur- 

 nished by different iron works. A new section has been 

 added on the strength of malleable iron and other metals, 

 with many new experiments on the strength of wrought iron, 

 gun-metal, brass, steel, &c. Several useful tables liave been 

 added, and the extent of the table of the properties of materials 

 nearly doubled. 



Mr.J. E. Gray has in the press, The Elements of Zoology; 

 containing, besides an Outline of Comparative Anatomy and 

 Physiology, and a Natural Disposition of the Animal King- 

 dom, with an analytical Table of the Genera, an Explanation 

 of all the Terms used in the Science, illustrated by numerous 

 Engravings. This work will be upon the })rinci{)les proposed 

 by W. S. MacLeay, Es<i., and the modern continental natu- 

 ralists. 



MonographiaTenthredinetarum* synonimia extricata. Auc- 

 tore Am. le Peletier de Saint-Fargeau, Socictatis Parisiensis 

 Historiac Naturalis Membro. Paris, apud Levrault, ISL'a. 



* The anpcaraiicc of this work niiiy interest the young Kiitonioh)gist, 

 whose inqmry relative to British Tcnthredo5 is. noticed at pp. 155 and IJIfi. 



Mr. 



