(721 ) 
Note^ that the circumference of the final left Pully or Roller 
B ^,upon which the Chair* isfaftened , is to be no bigger than 
7uft fo much fcope or diftance as che two Pannels make by che 
extremity of their umioft fwelling or (hrlnking ; and To one full 
revolution of the hand upon the Index may anfwer the fulleft 
fiirinking and fwelling in the year, and the diftance becween 
the two Rollers or PuTlies fixed upon the Axletree mart be the 
thicknefs of your Pannels ; fo that the Weight is to play or 
moveon the one fide of the Paqnel, and the Chain on the other, 
without difturbance or rubbing againft the fides of the Pannel 
or the Crofs, between which, out of fight, in the middle they 
are to be placed. 
This way was fo contrived t efore this time twelve-month, in 
the year 1675 ; fome years afcer the former 3 and fo with Chain 
and Pullies to avoid the (baking that would happen by apply- 
ing the work of Pinnion and teeth to move the bands ; which 
was then alfo propounded to Mr*r(?w;>/t^/; the Watchmaker, but 
by him rejefted, though I think that way may beufed alfo with 
a Weight added toregulate the motion. 
Now, as to the degree, to which the Deal-board, which fiiall 
ferve for thefe Inftrun^ents, is to be feafoned, and for the kind, 
of which the fame ought to be,you muft take the fineflftreight- 
eft grain of your Dram deal,as the beft for this ure,and let it lie 
drying ihyour houfe two or three years* And to know,whether 
it be fufficiently feafoned for this Inftrunient, take a fmall part 
thereof, and weigh it in a nice pair of Scales, and, if you find 
the weight thereof not to have increafed many grains in wet 
weather, nor decreafed many grains in dry, you may then con- 
clude this Wood to be fit for your purpofe. 
Occultatio 
