22 



THE EDDYSTONE ROCK- 



PART VI. 



keyed, 1 and the interstices were afterwards filled with 

 molten pewter. To these branches were firmly fixed 



a crown of squared 

 oak balks, and across 

 these a set of shorter 

 balks, and so on, till a 

 basement of solid wood 

 was raised, the whole 

 being firmly fitted and 

 tied together with tre- 

 nails and screw-bolts. 

 At the same time, to 

 increase the weight 

 and vertical pressure 

 of the building, and 

 thereby present a 

 greater resistance to 

 any disturbing ex- 

 ternal force, Rudyerd 

 introduced numerous 

 courses of Cornish 

 moorstone, as well 

 jointed as possible, and 

 cramped with iron. It is not necessary to follow the 

 details of the construction further than to state, that 

 outside the solid timber and stone courses strong upright 

 timbers were fixed, and carried up as the work proceeded, 

 binding the whole firmly together. 



Within these upright timbers the rooms of the light- 

 house were formed, the floor of the lowest, the store- 

 room, being situated twenty-seven feet above the highest 



' 



RUDYERD'S LIGHTHOUSE. 



1 Mr. Smeaton says that the in- 

 strument now called the Lewis, though 

 an invention of old date, was for the 

 first time made use of by Rudyerd in 

 fixing his iron branches firmly to the 

 rock. "Mr. Rudyerd's method," he 

 says, " of keying and securing, must 

 be considered as a material accession 

 to the practical part of engineering, 



as it furnishes us with a secure me- 

 thod of fixing ring-bolts and eye- 

 bolts, stanchions, &c., not only in 

 rocks of any known hardness, but 

 into piers, moles, &c., that have been 

 already constructed, for the safe moor- 

 ing of ships, or fixing additional 

 works, whether of stone or wood." 

 Smeaton's ' Narrative,' p. 22. 



