262. In addition the laboratory conducted the following investiga-tions:
(a) With the co-operation of Government Chemist and the Fisheries Research Unit of Hong Kong University, a total number of twenty-four samples of sea water taken at two places in the harbour were tested for their salinity and 'suspended solid' content.
(b) A series of tests were conducted to determine the coefficient of friction between concrete surfaces under varying conditions.
(c) Tests on the effect of powdered rubber mixed with bitumen 80/100 and M.C. 4.
(d) In connexion with the C.B.R. values and the stabilization of Hong Kong Laterite soils by hydrated lime.
ROADS OFFICE
Chief Engineer, F. A. Fisher, B.Sc., LL.B., A.M.I.C.E.
GENERAL
263. The work of this office steadily increased and additional staff brought the total up to over 1,500. A new post of Assistant Chief Engineer was established at the beginning of the year to assist in the office organization.
264. A Traffic Engineering Section was added to the sub-department for the specific purpose of preparing road widening schemes to improve traffic flow, besides designing road junctions, road marking and all aids to traffic on a sound engineering basis.
265. Over five miles of new road were constructed during the year and plans and surveys made for many extensions to spread the Colony's road network further into the New Territories and to permit additional development in Hong Kong and Kowloon. The decision to permit 8-feet wide vehicles to be used in the Colony rendered many of the existing roads dangerously narrow and necessitated new carriageways being planned with a width of 24-feet to cater for such vehicles.
266. Early in the year the planned programme of work was dis-located by exceptional rain storms which heavily taxed the resources both of the Roads Office and of the contractors carrying out the repair work. Despite this the lost time was made up in the latter part of the year and most of the original programme of works was successfully completed.
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The recently completed 175-foot high Tai Lam Chung Dam.
Steel & Concrete-The Tai Lam Chung dam nearing completion.