135 
by Mr. Rogerson, for the purpose of cleaning glass plates, 
and was quite satisfied it was an excellent method of cleaning 
glass. 
A paper was read “ On the Pantascopic Camera,” by 
J. R. Johnson, Esq. Communicated by E. C. Buxton, 
Esq. 
But a few years had elapsed since the introduction of the 
Daguerreotype, and photography had not yet passed beyond 
what may be termed “ The Daguerreotypic Era,” when the 
unsatisfactory nature of the bits” of landscape produced by 
the lenses then in use became fully recognized. What could 
be more annoying to an artist desirous of producing pictures 
of some of the splendid architectural monuments of Paris 
than to find that from no possible point of view could the 
whole of many of the finest of these be embraced ? 
The desirability of not only effecting this, but of repro- 
ducing as pictures some of those striking “ coups d’ceil” 
which abound on the banks of the Seine, struck an eminent 
artist-engraver, Mr. Martens, so forcibly that he immediately 
set about finding a remedy, and he was not long before he 
had attained his object. 
He found that if a lens be moved horizontally upon a pivot 
placed beneath its optical centre, the image is stationary 
notwithstanding the motion of the lens. 
Now as all subsequent rotating cameras are based upon 
this principle it is desirable that we should clearly understand 
it, and the instrument I am about to describe, and which is 
intended to be used for viewing panoramically views produced 
by a rotating camera, will enable us to do so. 
Fig. 1. 
