1870.] Notices of Scientific Works. 509 



of mechanics which are indispensable to all who follow the pro- 



In the chapter on retaining walls, the author should have 

 directed the student's attention to the various methods of con- 

 structing them, and should have explained the difference between a 

 vertical wall having its beds horizontal or perpendicular to its face, 

 and one with an inclined face, and the transverse section of joint, 

 perpendicular to that face. Also, in a brick retaining wall some 

 advantage would be derived from the disposal of the length of brick 

 or style of bond, and to the architectural student those are matters 

 of great importance, for in many cases practice seems to defy 

 theory. The author does not extend his chapters to the relative 

 strength of brickwork, nor to an account of the various kinds of 

 bricks made throughout England ; details which are now essential 

 in such a work, as bricks rank in these days amongst the most 

 important materials of construction. His chapter on arches might 

 also with advantage have been extended to the flat soffit and head 

 or cambre arch, showing the limit of span for a given depth and 

 breadth of face and soffit ; also to observations on the groin arch, 

 which would have imparted originality to his work. 



The remarks on mortar and cement are limited, and it would 

 have been well to refer to their tenacity and resistance to com- 

 pression, their suitability for various situations ; and the advantage 

 of the application of concrete to bad foundations. 



The information on centering of arches is also too much re- 

 stricted and too indefinite. The pressure of the voussoirs in a 

 pointed arch could not act on the centre at any of the angles in 

 the manner named by the author, and it would have been better 

 had he named the description of arch to which his remarks have 

 reference, as the pressure of the voussoirs differs considerably in 

 elliptic, pointed, and semi- or segmented arches. 



The chapter on iron does not refer to the segmental or curved 

 girder which is applied with much advantage in engineering, in 

 railway and other works. There is also room in the chapter for 

 observations on the trussed girder and the advantage or disad- 

 vantage of applying w^ought-iron flitch-plates to wood beams. 

 All these matters should have been referred to, so that the student 

 of the ' Science of Building ' (a title by the way which is likely to 

 mislead those who purchase it into the belief that it is an advanced 

 treatise) might be prevented from committing many errors into 

 which architects and builders are too prone to fall. 



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