Show MILE ROCK LIGHT One of ot the most conclusive proofs of the great strength and resistance endurance of structural steel and re- re enforced concrete combined is shown by the Mlle Mile Rock light station This little pharos stands as a beacon light sentinel at the southern entrance to San Francisco harbor the harbor the Golden Gate It has only been recently com com- completed Literally the light station is firmly anchored on the ragged pInnacle pinnacle pinnacle pin pIn- nacle of a rock which at extreme high tide was almost entirely covered with water A broad rim or shelf was slowly chiseled out around the rock some distance below the sharp and Jagged points A huge elliptically shaped cylinder of boiler boller steel five five- eighth of ot an Inch in thickness was wal built up from this shelf This cylinder was 40 feet high and feet In diameter It was fitted so as to cover the ragged tops of the rock lock All the thA space by the huge cylinder was filled with strongly enforced re-enforced concrete This material settled down downall downall downall all over and between the ragged points of oi the rocks and when the material was thoroughly set the whole mass became as one solid stone thus fur fur- an impregnable foundation and fortress against the fury of ot winds wind and waves All of the upper part of the station Is Cf strong structural steel steel massive massive massively ly braced and riveted The lower ends os of ot the steel skeleton are deeply anchored anchored Into the top ol of concrete cylinder From meat mean tl tic tide e e level the light Is Just feet feel above the water The total cost to the government of the station was wal f J One whole year was re re- required to complete the work This Thil Was Vas vel very largely due to the great en engineering difficulties and danger involved in In- In the construction tion and also alse alsoto to lo tho the small force Corce of men which could only be employed at a time to any advantage So perilous was the work that it was with no little difficulty the contractor could secure a dent clent force of cement rock and steel structural workers Work on the lower low low- er part of ot the structure could only progress during calm weather and on ebb tide For days at a stretch no work could be done at all The land Ing of material was always attended with great difficulties and aud peril and slowness However there was no loss of life nor even serious accident nt during the progress of ot the work |