234 



A DISCOURSE 



BOOK III. and converted as I have described it ; and it would likewise save a world 

 ^-'•'^^y^*^ of materials in the building of great ships, where so much excellent 

 timber is hewed away to spoil, were it more in practice. Finally, 



I must not omit to take notice of the coating of timber in work, used 

 by the Hollanders, for the preservation of their gates, portcullises, draw- 

 bridges, sluices, and other huge beams and contignations of timber expo- 

 sed to the sun and perpetual injuries of the weather, by a certain mixture 

 of pitch and tar, upon which they strew small pieces of cockle, and other 

 shells, beaten almost to powder, and mingled with sea-sand, or the scales 

 of iron, beaten small and sifted, which incrusts and arms it, after an in- 

 credible manner, against all these assaults and foreign invaders; but if this 

 should be deemed more obnoxious to firing, 1 have heard that a wash made 

 of alum has wonderfully protected it against the assaults even of that de- 

 vouring element ; and that so a wooden tower or fort of the Pirjeus, the 

 port of Athens, was defended by Archelaus, a commander of IVIithridates, 

 against the great Sylla. But you have several compositions for this pur- 

 pose, in that incomparable Treatise of Naval Architecture, written in 

 Low Dutch by N. Witsen, book i. chap. 5. The book is in folio, and 

 he that should well translate it into our language (which I much wonder 

 has not yet been done) would deserve well of the public. 



Timber that you have occasion to lay in mortar, or which is in any part 

 contiguous to lime, as doors, window-cases, groundsils, and the extremi- 

 ties of beams, &c. have sometimes been capped with molten pitch, as a 

 marvellous preserver of it from the burning and destructive effects of the 

 lime ; but it has since been found rather to heat and decay them, by hin- 

 dering the transudation which those parts require ; better supplied with 

 loam or strewings of brick-dust, or pieces of boards ; some leave a small 

 hole for the air. But though lime be so destructive whilst timber lies 

 thus dry, it seems they mingle it with hair, to keep the worm out of ships 

 which they sheath for southern voyages ; though it is held much to retard 

 their course : wherefore the Portuguese scorch them with fire, which 

 often proves very dangerous ; and ilideed their timber being harder, is not 

 so easily penetrable; and therefore have some been thinking of finding out 

 some tougher sorts of materials, especially of a bitter sap ; such as is re- 

 ported to be the wood of a certain Indian Pear : and some talk of a lixi- 

 vivum to do the feat ; others of a pitchy substance to be extracted out of 



