Notice respecting Mr Cutliberfs Elliptic Metals^ 6^c. 3^1 



The union of the well known features with the shroud must 

 have been a pure effort of or creation of the mind. There 

 seems, therefore, rlo reason why, dttder the same disposition of 

 the nervous system, any monstrous creations of the faculty We 

 call imagination, might not be produced to the eyes and other 

 senses, indeed, with all the qualities that constitute reality, ex- 

 cept their endurance, though this should hardly be excepted, 

 since there can be no reason why the appearances may not en- 

 dure, by a continuance of the conditions, for days or months; 

 I need hardly say that the relative whose ghost was seen after 

 so dismal a fashion, was at the time in perfect health. Had it 

 been otherwise, and that the apparition coincided with illness 

 or death, as has no doubt frequently happened in other in* 

 stances, our philosophy would have had to stand a severe triaL 



Art. XX. — Notice respecting Mr Cttthberfs Elliptic Metals 

 for Reflecting Microscopes. Communicated by a Correspond- 

 ent. 



Mr J. CuTHBERT has succeeded in obtaining perfect elliptic 

 figures for metals having an aperture equal to their sidereal 

 focus or 54°. The process by which he effects this is very si- 

 milar to that by which he obtains truly hyperbolic figures for 

 the mirrors of small Gregorian telescopes, of only five inches 

 focus and three inches of aperture. Many artists have at- 

 tempted to figure small metals having an aperture equal to 

 their focus, but the true curve is so perfectly artificial, that 

 they have hitherto been totally unable to attain it. It remain- 

 ed for the unique and peculiar talent of Mr Cuthbert, to a&. 

 complish this in metals of half an inch focus, and half an inch 

 of aperture, and three-tenths of an inch focus, and three-tenths 

 of an inch of aperture : — combined with an excelleM polish. 



When the scale of operation is so very contracted, we leave 

 it to those acquainted with such matters to determine how 

 small an error must inevitably destroy the figure of such mi- 

 nute mirrors. 



These metals are adajlted to the Amiciart catadioptric en- 

 giscope, (the perfection of which they consummate,) by means 

 of plane mirrors of very small diameter, when transparent ob- 



