he
improvement consists in arranging the knives so that one begins and
finishes its cut in advance of the other.

Mr. William Bradberry, of Darrtown, O., has invented an improvement in
reciprocating churns. The aim of this inventor is to utilize the
resistance of the milk as a source of power. To accomplish this a
peculiar combination of mechanism is required, which cannot be clearly
described without an engraving.

* * * * *

READING AND EYESIGHT.

M. Javel, in a recent lecture, tries to answer the question, "Why is
reading a specially fatiguing exercise?" and also suggests some
remedies for this fatigue. First, M. Javel says reading requires an
absolutely permanent application of eyesight, resulting in a permanent
tension of the organ, which may be measured by the amount of fatigue
or by the production of permanent myopy. Secondly, books are printed
in black on a white ground; the eye is thus in presence of the most
absolute contrast which can be imagined. The third peculiarity lies in
the arrangement of the characters in horizontal lines, over which we
run our eyes. If we maintain during reading a perfect immobility of
the book and the head, the printed lines are applied successively to
the same parts of the retina, while the interspaces, more bright, also
affect certain regions of the retina, always the same. There must
result from this a fatigue analogous to that which we experience when
we make experiments in "accidental images," and physicists will admit
that there is nothing more disastrous for the sight than the prolonged
contemplation of these images. Lastly, and most important of all in M.
Javel's estimation, is the continual variation of the distance of the
eye from the point of fixation on the book. A simple calculation
demonstrates that the accommodation of the eye to the page undergoes a
distinct variation in proportion as the eye passes from the beginning
to the end of each line, and that this variation is all the greater in
proportion to the nearness of the book to the eye and the length of
the line. As to the rules which M. Javel inculcates in order that the
injurious effects of reading may be avoided, with reference to the
permanent application of the eyes, he counsels to avoid excess, to
take notes in reading, to stop in order to reflect or even to roll a
cigarette; but not to go on reading for hours on end without stopping.
As to the contrast between the w