Miscellaneous Intelligence. 141 
tion of my first memoir, called the attention both of Mr. Ross and Mr. 
Powell to this subject, and strongly recommended them to make an in- 
strument to realize the anticipated eflect; their occupations, however, 
prevented either of these artists from taking the matter up. The year 
before last, previous to the publication of my second memoir, I again 
urged Mr. Ross, and subsequently Mr. Beck, to attempt its construc- 
tion, and for a short time they interested themselves in the matter, but 
ultimately relinquished it for want of time, and in my opinion over- 
estimating the difficulties-of the undertaking. 
It appears, however, from a communication in the * American Jour- 
nal of Science’ of January 1853, which has been reprinted in the last 
number of the * Microscopical Journal,’ that such an instrument has 
been actually constructed by Professor J. L. Riddell, of New Orleans, 
and the results expected have been obtained. The method Mr. Riddell 
employs is similar to the one | recommended to Mr. Beck. After the 
rays from the object pass through the compound object-glass in the usu- 
al manner, he deflects them by means of a system of rectangular 
le P, Cherubin d’Orléans, Capucin.’ This work was published at Pa- 
ris in 1677, and in it eight chapters and a plate are devoted toa minute 
description of the instrument, which he informs us he constructed, and 
pusehanes to the Dauphin. The following is an extract from the Pre- 
ace :— 
‘Some years ago I resolved to effect what I had long before pre- 
meditated, to make a microscope to see the smallest objects with the 
two eyes conjointly ; and this project has succeeded even beyond m 
expectation, with advantages above the single.instrument so extraordi- 
nary, and so surprising, that every intelligent person to whom I lave 
shown the effect has assured me that inquiring philosophers will be high- 
ly pleased with the communication. For this reason [ have determined 
to make it the principal subject of the present work.” 
And the second part, which contains a description of the instrument, 
is thus headed :— 
“Section the first, in which is taught the method of constructing the 
newly-invented microscope to see the smallest objects very agreeably 
and conveniently, represented entire to the two eyes conjointly, with a 
Magnitude and distinctness which surpasses everything which has been 
hitherto seen in this kind of instrument.” 
n the Pére d’Orléans binocular microscope, two object-glasses ke 
their lateral portions cut away so as to allow of close juxtaposition, and 
these nearly semi-lenses are so arranged, that their axe 
$ corres 
with the two optic axes passing through the tubes containing the ye 
ah 
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