 Initial work began on the rock on 7 August 1838 . Stevenson and 21 workmen arrived on board the sailing vessel Pharos and began to unload the barrack , whose massive legs were set into holes blasted out of the rock . After only two days the site had to be abandoned as a storm swept in from the Atlantic . It was a further six days before they could resume the punishing schedule of 16 hours a day work between 4 am and 8 pm . Fearing sea sickness , many of the man preferred to attempt to sleep on the damp rocks than on the ever @-@ rolling Pharos . 
