HISTORY OF SECURITY Security and security measures for protection of people, property and the environment have been in existence just as long as mankind. But, there are many types of security for different situations. For example, a bank note has built in security to stop forgery, and a boiler has a safety valve which blows off in case of too much pressure and prevents the boiler from bursting causing damage to property and person. To date the biggest security wall ever built is the Great Wall of China. The wall is some 2400km long, built from stones and wide enough to walk along the top. It provided defence against the Northern barbarians and was built in the third Century B.C. Just as well known is Hadrians Wall built in A.D. 122 by Emperor Hadrian to defend the Northern frontier of the Roman Province of Britain, its length is about 1OOkm. It is built of stone and about five metres in height. During the Medieval and Roman days the inhabitants of cities walled themselves in for the security. I am from one such city, York in England, where the wall has been preserved nearly all intact. During the same period Kings and Lords of the manor used to build castles and protect them with an outer wall and a moat filled with water, giving double security. Historically, walls have been used for security and/or a defence, and let us not forget in those days the enemy did not have RPG7 rockets, limpet mines etc and look at the measures they went to. That brings us to the modern day security wail. Not many years ago, requirements for walling was different from today's needs. What was good yesterday is not necessarily good today. Domestic and industrial security are different entities. The perimeter fence of a house is not generally a security fence as such, it is more for demarcating a boundary, keeping dogs and children in and a deterrent to thieves. Industrial security requires far more. Therefore, a more solid wall is required and more height with further fortification on top of this. There are quite a few aspects to be taken into consideration:   Visual access: Are the premises occupied at all times, do you want people, your competitors etc. to know what you are doing, or could theft take place through an open type fence.   Aesthetics: You have to live with the security. Therefore, if possible, it should be attractive. Let's go back to the early part of the article and consider those historical landmarks which, after centuries are still visited and form part of history. Let us hope that we leave some landmarks of security today for future reference. I personally do not consider the Berlin Wall a sight seeing visit for its heritage, but it brings to mind the ludicrous situation that people in Berlin were forced to live with. Maybe in 300 years time the site will be visited as Hadrians Wall is today. Today's security has to be cost effective for the situation required, without losing sight of whether visual access is or is not required, will it last the required period of time, upkeep, etc. Maintenance is costly and nobody really wants to spend money on it. It is labour intensive and expensive. Back to the original cost of security, take into consideration items that have been mentioned and remember that security is not always a fortification. Among well known modern security systems or fortifications were the Hindenburg Line of World War I and the Maginot and Siegfried Lines of World War II, none of which proved impregnable.