a 
ee 
Miscellaneous Intelligence. 143 
placed in a frame, with adjustments, so that, when applied to the eyes, 
separately see the reflected image of the projection 
which usually falls on that eye. This is not the case when the reflec- 
tion of an object is seen in a mirror; for then, not only are the projec- 
Sons of the flowers. A small terrestrial globe appears a concave hem- 
sphere ; when the globe is turned on its axis, the appearance and dis- 
appearance of different portions of the map on its concave surface has 
& very singular effect. A bust regarded in front becomes a deep hol- 
low mask ; when regarded en profile, the appearance is equally striking. 
framed picture, hung against a wall, appears as if im ed ina 
Cavity made in the wall. An object placed before the wall of a room 
*ppears behind the wall, and as if an aperture of the proper dimen- 
ons had been made to allow it to be seen; if the object be illumina- 
ted by @ candle, its shadow appears as far before the object as it actu- 
ally is behind it. 
od, Riddell’s Binocular Microscope.—On page 68 Dr. Riddell has 
sven a description of this important instrument. As figures, whic 
n° ate expecting from him have not arrived, we copy the following 
from a letter of his, published in the Boston Traveller of Dec. 8. 
b i 
a 
e 
il 
| 
KA 
: 
‘ Object to 3 
Mbjective combinati ; 
Pp : ination. , s 
tio “od rectangular prisms of fine glass, separating the rays by internal reflec 
- Uuter rectangular prisms, adjustable, for different distances between the eyes. 
Nip Send each bundle of frye in thé direction denoted by the arrows, to be receiv 
E, CCulars and erectors, also adjustable. : : bo’ 
AS FP > May be bivantod ae ined half way round, so that the object will be above. 
| Dr. Riddell prefers to have the stage fixed, and the slow motion for 
Adjustin the jectiv ade to affect the whole structure 
~0, Pp. slat of the objective, made to altect the 
