ENG-1963 — Page 222

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LAND AND HOUSING

Island and 109 of Kowloon and New Kowloon are now available in this series.

The New Territories remain largely rural, but the pressures of a rising population and an expanding economy have resulted in a striking growth of industry and housing. To meet this activity and to pinpoint individual land holdings a wide coverage of up- to-date survey sheets to a large scale is of first importance. To date, 379 sheets have been completed to a scale of 100 feet to an inch. As conventional ground methods of survey were proving too slow for the rapid pace of development, Messrs Hunting Surveys were engaged to fly and map the whole of the Colony at a large scale. The Crown Lands and Survey Office is providing all ground control and field checks on photo plots. These surveys form the basis for further scale plans which are required for planning, land records and other purposes and which are redrawn from photographic reductions. In addition to supplying survey sheets of the Colony showing the plan position of buildings, the survey division of the Crown Lands and Survey Office is also the responsible authority for establishing differences of level.

The first recorded levelling in the Colony was carried out in 1866 by HM surveying vessel Rifleman. For the purpose of sound- ings taken by this vessel a datum was established roughly at the then mean sea level. To provide a permanent record a copper bolt was driven into the wall of a storehouse in the Royal Naval Dock- yard and its height above the assumed datum measured. Since then this sounding datum later known as ordnance datum, has been taken as 17.833 feet below the level of Rifleman's bolt and is now known as principal datum. As the storehouse is to be demolished the bolt has been removed and re-erected at the new Naval Barracks. All levelling in the Colony is based on this prin- cipal datum which is approximately 3.9 feet below mean sea level. Town Planning. Town Planning in Hong Kong includes the planned development of new industrial townships, the redevelop- ment of out-of-date urban localities and the gradual expansion of the urban areas. The basic aim of the planning, therefore, is to provide a framework within which public and private development may progress together; to ensure that adequate provision is made for open spaces, public buildings, communications and other