UP4l 
of the Bone from one Table to toother about half an 
inch. 
Figure the 3d fliews the Revcrfe or Infide of the 
fame QiganUc\ Bone^ drawn likewife in as full propor- 
tion. What is moft obfervable in this Figure is the 
great thicknefs of the Bone, mark'd k k, which could 
not appear in t other pofture 5 and the fh^rp and high 
procefs of the Os Cribrofumy call'd by the Anatomifts 
Crifh Gallic marked 1. 
To prevent any miftake, 'twill be requifite to ob- 
(erve, that tho the dimenfions of both the larger and 
fmaller Bones as fet down, and the fize of them, as re- 
prefented in the Figures, do not juftly agree, it they be 
compared together, and examined by a pair of Gom- 
paffes : yet this difference is not occafion'd either thro 
any error in the Draughts, or any miftake in the mea- 
fures 5 but happens becaufe the dimenfions ar^ taken 
along the convex fide of the Bone, and fo includes the 
Sine of its Arch, which in the Draughts of necelTity 
was to be expreft only as it appears, by help pf (ha* 
dowing the Figures^ they being plans or flats 5 and to 
have done them otherwife, would have been to have 
drawn them falfe and prepofterous. 
By comparing thefeFigures,*tis evident what an exadt 
conformity there is in all particulars between this large 
Bone and the like Bone in a man of a juft height .5 and 
that they no ways differ but in magnitude : and as to 
the difference in fize between one and t'other, by their 
dimenfions we find the fmaller. did not anfwer the 
greater fo much as in half proportion : for where that 
meafured but four inches and a half, this was nine 
inches and one tenth 3 and where that was no more 
than fix inches, this was twelve inches two tenths, and 
fo forward : whence it follows, that this great Os 
Frontk was above twice as big every way as a common 
Bone of^ this fort in a man of full growth. 
Now 
