J' ' Zi^^/n^ /rt)^^^^W^ Moiyneux Efy; Sec. of 
. . /A^ Dublin Society ; to oneof the S. cf thefL 
invented by Him. 
I>ublin April) 17» %<^iS- 
F QR M^ant GffometMDg,><2tt;er^^to I ftall 
i>ri^y declare to yojaitiie cojatriv^^ pf^ Hygref-^ 
mp^y whigh I bavc latdy iavented ajidpujC ia .excPupioQ 
witb good XuGGcfo. I do not know that a»y has 
inen:tioned, w fojmiich.as hinted at the likCj .md ttiejce'- 
foi^e toijije fpi^tftlt^gether New; ^?Atit any me- has Jbc^e^ 
befpre-liaitid ^itkme,, JifluaJi not in ihelicaft contend foi: 
the Glory of it. 
Fig, i\ j4B, is a Whipcord about four foot long, tyed 
faft to the end of the Hook At the end of this Whip- 
jEjQtd -thexe Jiangs.ti^he-W^ight vabo^jc; j^.pc|ih;id- ^^9^^-^ 
vaud xarry 'vthe ||^dQX\i). -under t^i^^^ t^hete .placed a 
GriAduajt-fid the JBpard EF. Ep,t ^ Eragget 
againfl the Wall. ' 
All things being thus adapted, the moifture of the '^/V 
twifls the Rope and gives a motion to the Index over the 
divifions in the Graduated Circle; and again as the Jir 
grows more dry, the Cord untwifts and brings back the: 
Index by a contrary motion. 
That which firfl: gave me the Hint of this,was the oBferv- 
ing all Ropes tyed at both ends to be much more 
tite& ftretched harder after Rain has fallen on tliem then- 
before; I concluded that if I could (as it were,) ty a Rope 
at bothends and yet give one end a liberty of Cii^umvo-- 
JqioB.i, it would perforjoi mj defired endj now the 
Weight 
