204 
NATURE NOTES 
any one plate. From these three negatives prints are made in 
an ordinary frame under diffused daylight on gelatine-coated 
plates of mica. They are developed in warm water and then 
each is dyed in a solution of a colour complementary to that of 
the screen through which its negative was taken. The three 
monochrome positives on mica are then superposed and mounted 
between sheets of glass and the lantern slide is complete. As 
all the necessary accessories to any ordinary photographic 
outfit can be supplied for twenty-five shillings, and the process 
lends itself admirably to the treatment of flowers, mounted 
butterflies, polarised slides and other “ still life ” objects, it 
should become popular with nature-students. 
The Tele-photo Lens. — “Among the many moons most 
of us have longed for at various times are pictures of birds and 
animals just as they are in their natural surroundings. Russell 
Lowell used to say that a field-glass was a much better weapon 
than a gun for bringing the children of nature near to one. 
What a difference between the bird seen on the bough of a tree, 
singing in ‘ full-throated ease,’ instinct with life in every feather 
and movement, and the same songster, blood-smeared and fixed 
in death, as brought to the hand by the aid of a gun ! The 
lover of nature must prefer the field-glass. 
“ But the tele-photo lens is even better than the field-glass, 
for it will catch the image of the joyful bird and perpetuate its 
picture. It is not too much to say that this lens has opened up 
a new field of nature study, some of the results of which have 
already been reaped in the delightfully illustrated books on wild 
animals at home which have been published since the tele-photo 
lens came into use. Here are the practical facts in a nutshell. 
To approach as near a bird as is necessary with ordinary 
apparatus to obtain anything but a diminutive picture is almost 
impossible, but, on the other hand, to get the same-sized picture 
with a tele-photo lens the distance may be four, eight, or ten 
times as great. Suppose, for instance, it is required to photo- 
graph a starling on the edge of the hole in which its nest is built. 
To obtain a sufficiently large image with a g-in., lens and a half- 
plate camera the instrument cannot be more than three feet 
away. A tele-photo attachment fitted to the same lens, and 
adjusted to give a magnification of 8, would enable the photo- 
grapher to retreat with his apparatus to a distance of twenty-four 
feet and produce a similar picture. The value of this extra 
distance can hardly be over-estimated in photographing natural 
history subjects, where the close proximity of a camera is likely 
to disturb the object.’’ — From the Dioptric Review. 
