[ 7«o } 
the Guild-hall, London (8) ; which having been 
long fince loft, or deftroyed, we have nothing left 
whereby to difcover its true magnitude, but the mea- 
fures others have taken of it, and thofe which have 
fince been taken of fuch magnitudes as Greaves had 
compared with his copy of it. 
Snellius, from a meafure fent him of this iron 
ftandard (9), determined the proportion of the Rhyn- 
land to the London foot, as icoo to 968. The 
Rhynland foot, according to Picard (1), contains 
696 fuch parts as the Paris foot contains 720 : 
whence the proportion of the latter to this meafure 
from the iron ftandard, is as 1 065,4 to 997 nearly. 
Eifenfchmid found the Rhynland foot to contain 
1391.3 fach P arts as ^ ie ^ ar ^ s f° ot conta i ns J 44 ° ( * 1 2 3 4 ) J 
which gives 1065,4 to lefs than 9967, for the pro- 
portion of the Paris foot to that of the iron ftandard. 
Huyghens makes the Paris to the Rhynland foot as 
144 to 139 (3)} whence the proportion of the for- 
mer to Snellius’s London foot, will be nearly as 
1 065.4 to 995 i . But there is reafon to believe, 
that Huyghens’s meafure of the Rhynland foot was 
too fmall (4). 
(8) Greaves, p. 223. 
(9) Eratofthenes Batavus, p. 125. 141. 
( 1 ) See a paper intituled De Menfuris, in Divers Ouvrages de 
Mathematique et de Phyfique, par Meflrs. de l’Academie Royale 
des Sciences, Paris 1693, in folio, and afterwards printed in the 
4th vol. of Ouvrages adoptez. 
(2) Eifenfchmid de Pond, et Menf. vett. p. 94. 
(3) Horolog. Ofcill. part iv. prop. 25. 
(4) Picard, in his Voyage d’Uranibourg, p. 64. edit. Amff. 
fays, “ Paflant par Holland je pris l’occalion de verifier la pro- 
portion 
