48 Notices respecting New Books. 



Franiiiig, \vc are glad to observe, that the curve oj" equilibrium, 

 is considered to coincide with the neutral axis, as it must do j 

 also that this curve, is very properly determined from the nature 

 of the Load. In these points the Author has followed the best 

 examples, but by no means the most common ones. A few re- 

 marks found at the end of this Section, are worthy of being im- 

 jjrinted on the memory of every young Student. 



The second Section presents matter of high value : it is on the 

 Resistance of Timber; whereon we find a just distinction made, 

 between the strength and the stiffness oiTimheT ; and the latter 

 is shown to be, the only kind of Resistance that it is of use to 

 consider. The resistance to Tension, the resistance to cross 

 Strains, and the resistance to Compression, are each considered; 

 with practical Rules, and numerous Tables of Experiments, many 

 of which are new. 



The third Section is on the Construction of the Timbering for 

 Floors of Rooms: hereon, the Author has shown the futility of 

 the common method of Trussing Girders : which embraces the 

 ai)siudity, of an attempt to strengthen a Beam without adding 

 either to its dimensions, or the quality of its materials. 



The Laws of Resistance are here made to furnish practical 

 Rules, for calculating the dimensions of the different Floor Tim- 

 bers : and at the end, a curious Floor is described, which was 

 executed at Amsterdam, for a Room of 60 feet square : the Floor 

 altogether, only 4y inches thick, and yet so bonded together, as 

 to be sufficiently strong. 



The fourth, Jifih and sixth Sections are, respectively, on the 

 Construction of Roofs, Domes and Partitions, with designs for 

 different kinds of each, and rules for calculating the dimensions 

 of their Timbers. It has been an opinion, that the Italians are 

 better Carpenters than the French ; two Roofs that have been 

 executed in Italy, and are here described amongst the Examples, 

 tend to confirm this opinion ; but although such Roofs differ iu 

 principle, from those particularly described and calculated by the 

 Author, he has omitted to give the proper proportions for their 

 Timbers, which would have been valuable to the Student. An- 

 other of the Examples, describes a Russian Roof of 235 feet span ! 

 of which the design is very good. 



The seventh Sec'.ion, treats very fully of the temporary Cew/rin^ 

 for Stone Arches, and on the methods of computing the pressure 

 of the Arch Stones, and strength of centring necessary for ef- 

 fectually supporting them : two original designs for Centres are 

 here given, contrived according to the principles of constructioo 

 pointed out by the Author. 



The eighth Section is on the construction of wooden Bridges, 

 and is by far the most complete Treatise on this subject, which 



