Book HL of Trunks. 
ur 
6. $. Wherefore, Cowvolowía's do not wind by any peculiar Na- 
ture or Genius, which other Trunks have not 3 but becaufe their Parts 
are difpofed fo, as to render them more fequaceous to the external 
Motor. Even as the Clafpers of a Vine, having the like struéfure, have 
alfo a Motion of Convolution : whereasthe Branches themfelves upon a 
contrary account, move in a firaight Line. 
7. $. The Convolution of Plantshath been obferved only in thofe that 
Climb. But it feems probable, that many others do alo winds in 
which, the main Stalk, is as the Axis to the Branches round about. Of 
B. 2.P.x: 
which number, I conceive, are all thofe whofe Roots are twilted 52 Ch. r. 
Motion we obferved in {peaking of the Root. Whether it be fo, or 
not the Experiment may eafily be made by tying a Thred upon any of 
the Branches ; fetting down the refpeét it then hath to any Quarter in 
the Heavens : for, if it (hall appear in two or three Months, to have 
changed its Situation towards fome other Quarter; it is a certain proof 
hereof. And that hereby the Roots of many Plants become twilted 5 
the Motion beginning in the Stalk, and ending at the bottom of the 
Root, which ftands always fixed in the fame place. 
8. $. The Convolution of Trunks, is made not one, but divers ways 5 
fome moving by South from Eaft to Weft ; and others from Weft to Eaft. 
Wherefore it feemeth, that as the Efficient Caufe of Convolution, is not 
within the Plant, but external: fo alfo, that it is not Ove,but that there 
are Two Great Efficients of this Motion; fe. the Sun and the Moon, 
Some winding together with the Sw», in its Diurnal Motion, ( or, if the 
the Earth moves, then, Inclining to the su» ) by South from Eafi to 
Weft. Ang others winding with the Moo», in its Monthly Motion, from 
Weft to Bafi. 
i $. E, pofüibly, may alfo be one fenfible way of diftin, vifhing 
betwixt Solar, and Lunar Plants, Thus far, in general, of the Motions 
of Trunks. 
CHAP. VIL 
Of the Nature of Timber or Trunks, as they 
ferve for Mechanick Ufe. 
ZA H E laft thing I purpofed to fpeak of, is, Thofe 
feveral Qualities of Timber or of Trunks, by which 
they are fitted for Mechanical Ufe. As Hardnefi, 
Softmefs, Fafinefs, Clevefomenefs, Toughnefi, Britile- 
$ nefi, Durablenefs, or any of the fame Qualities 
compounded. The Päfble Canfes whereof are ob- 
fervable, Partly, in the Struéfure of the feveral 
Parts; fe. the.Infertions, Sap-Veffels and Aer-Veffels; as to the Num- 
ber, Size, Or Pofition of any of them. And partly, in the Nature of 
the Parts 5 I mean fuch as is manifeft to fenfe. According to our clear 
and diftinét obferving of all which Caufes, we may underftand, 
Wherefore any Wood is made ufe of for any certain purpofe. And 
alfo, wherein fitly to apply it to further Ufe. In order to which, a 
Aa compleat 
