ILL 
IMI 
trating and adorning books. Besides the 
writers of books, there were artists whose 
profession was to ornament and paint manu- 
scripts, who were called illuminators ; the 
writers of books first finished their part, and 
the illuminators embellished them with or- 
namented letters and paintings. We fre- 
quently find blanks left in manuscripts for 
the illuminators, which were never filled 
up. Some of the ancient manuscripts are 
gilt and burnished in a style superior to 
later times. Their colours were excellent, 
and their skill in preparing them must have 
been very great. The practice of intro- 
ducing ornaments, drawings, emblematical 
figures, and even portraits, into manu- 
scripts, is of great antiquity. Varro wrote 
the lives of 700 illustrious Romans, which 
he enriched with their portraits, as Pliny 
attests in his “ Natural History.” Pom- 
ponius Atticus, the friend of Cicero, was the 
author of a work on the actions of the great 
men amongst the Romans, which he orna- 
mented with their portraits, as appears in 
his life by Cornelius Nepos. But these 
works have not been transmitted to poste- 
rity. There are, however, many precious 
documents remaining, which exhibit the 
advancement and decline of the arts in dif- 
ferent agqs and countries. These inestima- 
ble paintings and illuminations display the 
manners, customs, habits, ecclesiastical, 
civil, and military, weapons and instru- 
ments of war, utensils and architecture of 
the ancients ; they are of the greatest use 
in illustrating many important facts relative 
to the history of the times in which they 
were executed. In these treasures of anti- 
quity are preserved a great number of spe- 
cimens of Grecian and Roman art, which 
were executed before the arts and sciences 
fell into . neglect and contempt. The ma- 
nuscripts containing these specimens form a 
valuable part of the riches preserved in the 
principal libraries of Europe. The Royal, 
Cottonian, and Harleiau Libraries, as also 
those in the two universities in England, the 
Vatican at Rome, the imperial at Vienna, 
the royal at Paris, St. Mark’s at Venice, 
and many others. A very ancient MS. of 
Genesis, which was in the Cottonian Li- 
brary, and almost destroyed by a fire in 
1731, coutained 250 curious paintings in 
water-colours. Twenty-one fragments, which 
escaped the fire, are engraven by the so- 
ciety of antiquarians of London. Without 
mentioning others, we may observe that 
Mr. Strutt, has given the public an oppor- 
tunity of forming some judgment of the de- 
gree of delicacy and art with which these 
illuminations were executed, by publishing 
prints of a prodigious number of them, in 
his “ Regal and Ecclesiastical Antiquities 
of England,” and “ View of the Customs, 
&c. of England.” In the first of these works 
we are'p resented with the genuine portraits, 
in miniature, of all the kings, and several of 
the queens of England, from Edward the 
Confessor to Henry VII. mostly in their 
crowns and royal robes, together with the 
portraits of many Other eminent persons of 
both sexes. The illuminators and painters 
of this period seem to have been in posses- 
sion of a considerable number of colouring 
materials, and to have known the arts of 
preparing and mixing them, so as to form a 
great variety of colours : for in the speci- 
mens of their miniature paintings that are 
still extant, we perceive not only the five 
primary colours, but also various combina- 
tions of them.. Though Mr. Strutt’s prints 
do not exhibit the bright and vivid colours 
of the originals, they give us equally a view, 
not only of the persons and dresses of our 
ancestors, but also of their customs, man- 
ners, arts, and employments, their arms, 
ships, houses, furniture, &c. and enable us 
to judge of their skill in drawing. The 
figures in those paintings are often stiff and 
formal ; but the ornaments are in general 
fine and delicate, and the colours clear and 
bright, particularly the gold and azure. In 
some of these illuminations the passions are! 
strongly painted. After the introduction 
of printing, this elegant art of illuminating 
gradually declined, and at length was quite 
neglected. 
IMAGE, in optics, is the appearanee of 
an object made either by reflection or re- 
fraction. In all plane mirrors, the image is 
of the same magnitude as the object, and it 
appears as far behind the mirror as the ob- 
ject is before it. In convex mirrors, the 
image appears less than tire object ; and 
farther distant from the centre of the con- 
vexity, than from the point of reflection. By 
the following rule, the diameter of an image 
projected in the base of a convex mirror, 
may be found. “ As the distance of the 
object from the mirror is to the distance 
from the image to the glass, so is the di- 
ameter of the objcct.to the diameter of the 
image.” 
IMAGINATION, a power or faculty 
of the mind, whereby it conceives and forms 
ideas of things communicated to it by the 
outward organs of sense. 
IMITATION, in literary matters, the 
