LIFT BRIDGE OVER THE MURRAY AT SWAN HILL. Cclll, 
was probably the oldest type known, having been used in crossin 
moats, affording a thoroughfare when down and a protection 
when up. 
Consideration No. 2 was rendered unnecessary if No. 1 was 
proved incorrect. 
No. 4 can be equally as easily provided in either type, as also 
Nos. 5 and 6. 
In Engineering News, No. 19, Vol. xxxvi., a leader on the 
design of moveable bridges said, amongst other interesting matter, 
“Tt is true in engineering work as in every other industry, that 
the force of precedent and custom is exceeding powerful and often 
leads to the adoption of a certain pattern or type of structure or 
machine, not because it is the best that could be devised, or that 
is offered, but because custom has sanctioned it and anything else 
is an innovation.” These words were no doubt true in a general 
Sense but he did not consider that they applied to the author, as 
he gave him credit for being free from such fine old, crusted, con- 
Servative feeling. 
There was no doubt that the vertical lift bridge, as described, 
was counterbalanced effectively when being operated, but this 
very desirable essential could be effected, and has been, in a 
variety of ways, in a bascule opening. 
The author in describing the alterations to the Bourke Bridge 
in 1895 stated the arrangement of the wire ropes was designed 
by Mr. de Burgh, and then proceeded to describe the arrangement ; 
after a careful perusal of this description, Mr. Haycroft was of ; 
Opinion that it was practically identical with the arrangement of 
the wire ropes used by J. A. L. Waddell, M. Am. Soc. C.E., cg the 
Halstead Street Bridge at Chicago: a very full description of 
of this structure would be found in the Transactions of the 
American Society of Civil Engineers, Vol. XXXII. Mr. vee 
having read his paper in Nov. 1894. He possessed blue prints of 
the drawings of this bridge, kindly sent him by Mr. Waddell, 
where of course the arrangement of ropes was similar to that 
described in the volume referred to. 
