° * 
The Daguerreotype and its Applications. _ = 
In Daguerreotype miniatures, moles, freckles and even hairs are 
copied with microscopic accuracy. The iris of a dark eye is 
sharp and distinct, and the white dot of light upon it, is given 
with surprising beauty. If the iris is of a light blue, it is liable 
to solarize, before the face and dress make any decided impression 
on the iodized surface. This minute accuracy is preserved in 
the very small miniatures, intended to be worn as ornaments. 
The general sharpness of the portrait is probably increased by a 
diminution of its size, and with the aid of a lens all the “individ- 
ual peculiarities’ may be discovered. By enlarging the dimen- 
sions of the portrait, this character is impaired, and entirely dis- 
appears when the face becomes two inches in length. See Amer- 
ican Repertory for October, p. 209+—Professor Draper’s paper on 
this subject. 
Mr. Wolcott’s external arrangements are similar to those already 
described. If the sun’s light is employed, the ray is directed by 
a looking glass to the sitter, whose eyes are defended by an inter- 
posed blue glass. 
An elliptical metallic mirror seven inches in diameter, and of 
twelve inches focal length, is secured at the back of a box open at 
one end. Within this box, and near its open end, is placed the 
Movable frame which supports the plate. In operating with this 
apparatus, the sitter should be about eight feet distant from the 
open end of the box; the plate with its iodized surface facing the 
mittor is then placed in the frame previously adjusted to the focus. 
The time required for the camera operation varies from 4m. to 
2m., if the sun’s light and the mirror are employed; 3m. are ne- 
“essary to its completion in diffused light. 
In this apparatus the position of the plate between the sitter 
and the metallic mirror, limits its size. Originally this limit was 
two inches Square ; improvements however, have been made by 
Mr. Wolcott, which enable him to use them of larger dimensions. 
This apparatus possesses some decided advantages over that fit- 
ted with lenses. Portraits can be taken when the sun is obscur- 
ed by clouds, and the picture is not reversed; that is, the right 
and the left hand do not change places. ; 
Mr. Ibbotson, of London, has succeeded in copying magnified 
images by artificial light. That from lime rendered incandescent 
by the flame of the oxyhydrogen blowpipe, is said to be suffi- 
lently intense for this purpose, and produces the result in a 
shorter period than solar light. os 
