792 
SUMMARY OP CURRENT RESEARCHES RELATING TO 
scope. Tlie first column contains the number of the image ; the second 
the distances e of the front face of the objective from the upper face of 
the diffraction plate ; the third column gives the position of the image 
in which the normal image (No. IV.) is reckoned as “normal,” the 
inverted ones as “ abnormal ” ; while the fourth column shows the rela- 
tion of the magnifications : — 
Image. 
e. 
Position. 
Relation of 
Magnifications. 
I. 
mm. 
0-50 
Normal 
3-21 
II. 
415 
1-00 
III. 
8-55 
Abnormal 
0-61 
IY. 
12-70 
Normal 
1-00 
Y. 
25-05 
Abnormal 
1-09 
The objective aa of the Zeiss Microscope consists of two lens systems. 
The front one of these is a plano-convex lens, the plane face of which 
forms the front surface of the whole objective. The front face of the 
second system is convex. The author shows that the surfaces concerned 
in the phenomenon under examination are — a , the plane front face of the 
objective ; b, the back surface of the plano-convex lens ; and c, the convex 
front face of the second system of the objective. By means of the 
ordinary rules for reflection at plane, concave, and convex surfaces he 
demonstrates that the effect of a is to produce the image II. with magni- 
fication equal to that of the normal image IY. ; that from b result the 
images I. and III. with magnifications, as compared with image IY., of 
3*29 and 0*62 respectively, which agree very closely with the actual 
numbers given in the above table ; and that c is responsible for image V., 
which should theoretically have a magnification of 1*10 as compared 
with that of image IY. 
(6) Miscellaneous. 
The late Mr. Charles Baker, F.R.M.S. — Mr. J. E. Ingpen, at the 
meeting of the Society on October 18th, made the following remarks : — 
“ By the death of Mr. Charles Baker, the optician, of High Holborn, 
a Fellow of thirty years’ standing, a link between the earlier and later 
stages of microscopic work has been severed ; a few words of reference 
to his share in that work may, therefore, perhaps, be not out of place. 
When, some five-and-forty years ago, Mr. Baker turned his attention to 
Microscope manufacture, good Microscopes were very scarce and expensive, 
and students’ Microscopes, in the present acceptation of the term, almost 
unknown. By the introduction of French objectives, which were of 
very good quality, and their adaptation to simple and serviceable stands, 
the Microscope was placed within the reach of many who could not afford 
to purchase the higher class work. In more recent times Mr. Baker 
was chiefly instrumental in introducing into this country the optical 
improvements developed by Prof. Abbe and Dr. Carl Zeiss, which have 
given so great a stimulus to microscopical research,, and of which our 
English opticians have so wisely availed themselves. 
Mr. Baker veiy rarely attended our meetings ; but his establishment 
