CHAPTER XIII.

LIGHTING STREETS.

Gas v. Electricity -- Public Health Act on lighting -- Different hours at which public gas lamps are lighted -- Hints for a contract with a gas company -- Supply by meter -- Objections to meters -- Regulators -- Lamp-posts -- Lanterns -- Burners -- Numbering lamps -- Formula for determining distance of lamps -- M. Servier on spreading light uniformly -- Tables of different lights -- Points to be considered in public lighting by electricity -- Motive power required -- Machinery necessary -- Regulations as regards fire risks -- Lamps -- Value of electric light -- Difficulty of photometrical measurement -- Cost of electric light -- Mr. Shoolbred’s tables -- Comparative cost on Thames embankment -- Value of these investigations -- Acme of all lighting 129