PREFACE. 
The following tables are construcffed for the purpose of determining 
by inspection, or by simple multiplication and division, the dimensions 
of any description of timber requisite to carry a given weight, or to 
have, when loaded, a given deflection. They are designed for the use 
of Architects, Builders and Carpenters; Engineers, Ship Builders, 
Surveyors ; and others, who may be in any way interested in converting 
timber into scantlings for building purposes generally, or for otherwise 
sustaining transversely any given pressures. 
The outline of the work may be stated as follows : — 
The timber selected as the unit or standard of comparison, is Red 
Pine of a given strength and elasticity ; and the constants for various 
species of timber are derived from the mean results of an extensive 
series of Experiments made principally by Professor Barlow, upon 
" woods not of the best but more common quality, in order to furnish 
" data for practical cases," the specimens for that purpose having been 
selected from all the timber in store in Woolwich Dock Yard. 
For the convenience of reference, and in order to keep the subjects 
distinct, the work is arranged in four divisions ; namely. Three Series 
of Tables and several Miscellaneous Tables. 
By the First Series of Tables may be found the Scantlings of Red 
Pine, and thence by a Table of Constants those of any other descrip- 
tion of timber, sufficient to carry given heavy weights, and to have when 
loaded given deflections. 
The Second Series or Tables of Weights shew one-eighth of the 
breaking weight in cwts. uniformly loaded, or one-fourth of the same 
when suspended from the middle, of Red Pine of any usual scantling 
