CHAP, xviii S Y L V A 157 



sprouting. In setting the trunchions, it were not 

 amiss to prepare them a little after they are fitted to- 

 the size, by laying them a while in water ; this is also 

 practicable in willows, &c. 



4. Of old they made boats of the greater parts of 

 this tree, and excepting Noah's ark, the first vessels 

 we read of, were made of this material. 



When hollow alders first the waters try'd, 

 8 And down the rapid Poe light alders glide. 



And as then, so now, are over-grown alders frequently 

 sought after, for such buildings as lie continually 

 under water, where it will harden like a very stone ; 

 whereas being kept in any unconstant temper, it rots 

 immediately, because its natural humidity is of so 

 near affinity with its adventitious, as Scaliger assigns 

 the cause. Vitruvius tells us, that the morasses about 

 Ravenna in Italy, were pil'd with this timber, to 

 superstruct upon, and highly commends it. I find 

 also they us'd it under that famous Bridge at Venice, 

 the Rialto, which passes over the Gran-Canal, bearing 

 a vast weight. Jos. Bauhimus pretends, that in tract 

 of time, it turns to stone ; which perhaps it may 

 seem to be (as well as other aquatick) where it meets 

 with some lapidescant quality in the earth and water. 



5. The poles of alder are as useful as those of 

 willows ; but the coals far exceed them, especially for 

 gun-powder : The wood is likewise useful for piles, 

 pumps, hop-poles, water-pipes, troughs, sluces, small 



1 Tune alnos primum fluvii sensere cavatas. 



Georg. i. 



s Nee non & torrentem undam levis innatat alnus 

 Missa Pado ... 2. 



