PROCEEDINGS OF THE SOCIETY. 
295 
altered from that of a telescope down to that of a 4 in. objective. The 
other plan was simply ludicrous as turning the Microscope into a very 
indifferent telescope. 
Mr. Mayall said the instrument described by Mr. Charters White 
was known in the last century as the “ Megaloscope,” and had been 
constructed by B. Martin, both as a dioptric instrument and as a cata- 
dioptric ; in the latter case an ordinary short-focus Gregorian reflecting 
telescope was so arranged that the distance between the reflectors could 
be increased so as to enable moderately near objects to be seen magnified. 
The plan adopted by Dr. Matthews was simply to adjust a low-power 
Microscope objective or a Kellner eye-piece in the substage, which he 
directed towards the object, or to a plane mirror in which it was 
reflected, and then he viewed the aerial image with the compound Micro- 
scope above. The difference between Dr. Matthews’s plan and that of 
B. Martin was principally in the employment of achromatic objectives, 
which he believed had been first used in this way by Charles Chevalier. 
Mr. Mayall quite agreed with Mr. Nelson that such an arrangement was 
a very inferior way of building up a telescope for viewing moderately 
near objects ; though it should be remembered that the late Dr. Royston 
Pigott fully believed he had been able to resolve about the one-millionth 
of an inch by such an arrangement, the fallacy of which had been con- 
clusively demonstrated by Prof. Abbe in the Journal of the Society. 
But M. Fayel’ s arrangement was not open to Mr. Nelson’s criticism 
regarding the angle of aperture, which applied, of course, when the 
projecting lens — the object-glass of the megaloscope — was a Microscope 
objective of very small linear aperture. M. Fayel proposed to use as 
the object-glass of his megaloscope a photographic lens of which the 
linear aperture would doubtless be very much larger than that of any 
Microscope objective, and the linear aperture would be proportionately 
more effective when utilised telescopically. The linear aperture of 
Microscope objectives of even 4 in. or 5 in. focus was practically limited 
by the diameter of the Society screw to something less than an inch ; but 
many photographic lenses had been constructed of 4 in. to 6 in. focus, 
with linear apertures of 2^ in. to 3^- in., and these might be employed in 
the manner suggested by M. Fayel more effectively than Microscope 
objectives, collecting very much more light. He (Mr. Mayall) did not 
suppose that M. Fayel proposed this method of observation to supersede 
the recognized employment of low powers on the Microscope, but rather 
to meet the case where objects were to be viewed which could not be 
conveniently examined with an ordinary Microscope. 
Prof. Bell gave a resume of a paper by Dr. W. B. Benham “ On 
Eminia equatorialis, a new earthworm Irom Equatorial Africa,” ex- 
plaining that the specimen described had been found by Emin Pasha, 
and forwarded to the Natural History Museum, whence, by permission 
of Dr. Gunther, it had been sent to Dr. Benham for examination. 
Unfortunately, it was the only specimen collected, and its small size 
and immature condition made it difficult to say exactly what position 
should be assigned to it. There seemed no doubt as to its being a 
new genus. Dr. Benham’s paper, minutely detailing such observa- 
