5 « 
286 WILLIAM FIELD HOW. 
ensured if this were not done. Engineers occasionally require 
bridges to be tested by loading them at the manufacturer’s works, ° 
in which case, turned bolts to fit the rivet holes must be used ; 
but such testing is very seldom insisted upon. ay ¥ 
When erected on the maker’s premises, the work is carefully 
painted, and in the case of bridges, considerable facilities are 
afforded to those who have the handling of the work at the site of 
delivery, if the main girders are painted different colours, and the 
portions of the cross girders adjacent to them also coated with the 
same shades. In lattice bridges, it is advisable to paint the bottom 
portions of the bars, and the webs of the booms to which they are 
fixed, black, upon which the stencil marks show up clearly ; and 
in addition to the stencil marks, the figures and letters are also 
stamped into the work, to provide against any painted marks being 
obliterated in transit. Plans showing the colouring and marking 
of the work are also supplied for use of the erectors. 
In concluding this paper the author would point out that to 
ensure good workmanship and material, it is advisable to place 
contracts in the hands of reliable firms. If they are let to manu- 
facturers who have not a high reputation, who will, if possible, — 
scamp their work and evade portions of the specification, then it 
is impossible to obtain reliable and uniform material and work- 
manship, no matter how capable and strict the supervising officers 
may be. 
Results of some experiments made upon five pieces of Spike’ 
Steel, three-quarter inch diameter, cut from one bar, and five pieces 
of Bolt Steel, seven-eighths inch diameter, cut from one bar. 
