Memoir of Rev. John Prince, LL. D. 209 
self upon a simple plan, the effects of which are surprisingly mag- 
nificent and beautiful. It is also a noble megaloscope as well as 
microscope, the field of view being an inch and a half diameter, with 
considerable magnifying power. The body of the instrument is 
four feet and a half in length, including the brass tubes at the end 
for the magnifiers. It is made in the form of an obelisk, and when 
it is not in use as a microscope it stands upright on its base; the 
tube in its top is unscrewed and a small urn is put in its place, so 
that it makes a handsome ornament in a room, and is more out of 
the way than if laid in a horizontal case.” 
- In a letter, dated March 2d, 1801, he gives the Messrs. Jones a 
particular account, accompanied by models and diagrams, of addi- 
tional improvements, made by him in the magic lantern. 
In a letter to the same persons, Nov. 24, 1818, he describes a 
very important and beautiful improvement he bad just made on Dr. 
Brewster’s kaleidoscope. He constructed it in such a manner that 
it was brought to bear upon opake objects, and most splendid and 
magnificent were the combinations of dazzling colors thus brought 
to light—a world of wonders, the brilliancy and glory of which tran- 
scended all that the eye of man ever contemplated, or his imagina- 
tion conceived, was revealed to view, as existing in the darkest and 
roughest metals and rocks beneath our feet. 
The following extract is from a letter to the Messrs. Jones, Oct. 
28, 1823. <I have .sent you, in the same box with the telescope, 
part of a hydrostatic instrument which I began to make with some 
others several years ago, and now my health and age will not allow 
me to finish it. It is a combination of several instruments. I have 
made three of them for different colleges. It is much approved, and 
more are wanted. I thought that by sending the parts done, with 
their description and uses, and some models of the parts to be added, 
it would give you a better idea of it than a mere description alone. 
Dr. Prince continued his labors, as a philosophical mechanician, 
to a very advanced age. He thus alludes to them, ina letter tothe 
Messrs. Jones, May 26, 1826: “I have been so much pleased 
with the large solar microscope I made, of which I wrote you some 
account, that | am making another with a large enlightening lens. 
My age and infirmities will not permit me to make another after 
have finished this. One experiment I make with it is very pleasing 
and much admired. It is an imitation of an eruption of a volcano, 
by burning Dutch sealing wax, which melts but does not run freely. 
Vou. XXX1.— 27 
