25 2 
Dr. Wollaston on the 
glaringly ill-suited to that of the rest of the face, the effect 
is impaired by such obvious discordance, but is not altogether 
lost ; for though some persons much accustomed to drawing 
the human eye, who are in the habit of attending minutely to 
the shape of the lids, may not feel the full effect perceived by 
others, still the change of direction that is admitted by the ge- 
nerality of those who have nothing to warp their judgement, 
shows how little influence the eyelids really have in giving 
apparent direction, in comparison with the more prominent 
features. 
In order to show how small an addition is sufficient to pro- 
duce the effect, in Plate X. are four copies of another represen- 
tation of the same pair of eyes made exactly alike by the ad- 
mirably ingenious process of Mr. Perkins. A strong plate 
of steel on which they were first engraved, having been subse- 
quently hardened, gave an elevated impression of them to a 
soft steel roller, passed with great force repeatedly over the 
surface of the plate. The roller having next been hardened in 
its turn, became the tool for transferring four impressions to 
the same plate of copper, with the most unquestionable iden- 
tity of representation in the four copies to each other. Never- 
theless in two of these their apparent direction will be seen 
to differ by the mere position of the noses, and in the others a 
corresponding difference is effected solely by means of the 
upper half of the face. 
For the sake of greater perspicuity, we have hitherto con- 
sidered merely the cases of lateral turn of the eyes and face, 
at small angles of deviation to the right or left, by the balance 
of which, if in opposite directions, the eyes appear to look at 
us ; or, if the inclination of both be toward the same side of 
