ANNIVERSARY ADDRESS. 35 
The lift span is formed of two steel Warren girders, carrying a 
timber deck, the total weight of the span being about thirty-four 
tons. This is counterbalanced by four cast iron balance boxes 
filled with lead, which are connected to the span at each corner, 
and work over large rope wheels fixed in the top of wrought iron 
braced towers. The lift span differs from its predecessors in that 
the span is worked from the deck level instead of from a platform 
at the top of the towers ; and with the new arrangement of the 
shafting and gearing one man can open the span in five and a 
half minutes, through the full height of the lift, which is twenty- 
five feet in this case, as against twenty-one feet in previous bridges 
of the same type. The metal work for Swan Hill bridge was 
manufactured in Melbourne, and the whole of the timber, with 
trifling exceptions, obtained from the northern rivers of New 
South Wales. 
Among the miscellaneous works carried out during the year 
was the wood blocking of portions of the Circular Quay near the 
P. & O. Wharf, in which blackbutt, tallow-wood and red mahogany 
blocks were used, laid in sections, to allow of the relative wear 
Under traffic being observed and compared. At the present time 
the Branch is engaged upon a number of important works, includ- 
ing new bridges over the Tweed River at Murwillumbah, Paterson 
River at Dunmore, Queanbeyan River at Queanbeyan, Stone 
Quarry Creek at Picton, and the Macleay River at Kempsey. 
The design for Kempsey bridge includes four one hundred and 
fifty-three feet timber truss spans of a new design; these will 
be the largest Spans in the colony constructed wholly of timber. 
For the above information (other than that referring to railway 
and tramway matters), I am indebted to Mr. R. R. P. Hickson, 
| MInst.c.z., Under Secretary for Public Works and Commissioner 
for Roads, and to Mr. Cecil Darley, M. Inst. c.E., Engineer-in-Chief 
for Public Works, _ 
8. Pustic Hearru.—In giving some account of the work of 
the Board of Health and of its scientific staff, during the past 
Year, it is only proper for me to point out that duties connected . 
