NATURAL HISTORY MISCELLANY. 191 
relation of the object to the focus. This difficulty is met chiefly 
in the use of small, single lenses, that are held in the hand, and 
it may be safely said that a single hour’s work, with a lens of this 
description held in the hand, or mounted on an unsteady stand, 
will cause more injury to the eyes than weeks of work where a 
first-class instrument of far higher power is used. It has always 
seemed to us that watch-makers, engravers, and those who use 
lenses, do not sufliciently appreciate this fact. They, in general, 
mount their lenses on wire stands, which tremblingly respond to 
every footstep that falls upon the floor, and thus cause continual 
demands upon the eye for re-adjustment of focus. So, too, we 
have seen students of botany poring over plants by the hour, and 
using a small hand-lens, which must have been utterly destructive 
to the eyes. Wherever a microscope— single or compound —is 
used for more than a few seconds, it ought to be mounted upon a 
stand so firm that all vibration, and especially all disturbance of 
the focussing, will be avoided.— Good Health. 
ANTHROPOLOGY. 
PROBABLE Important ARCHÆOLOGICAL Discovery. — In these 
days of archeological humbugs we hardly venture to copy any 
account of a reported discovery, but feeling confident that Mr. 
Meehan would not have printed Mr. Douglas’s letter unless he 
knew him to be a reliable observer, we give the following :— Mr. 
H. Doveras, of Waukegan, Ill., writes to Mr. Meehan (who has 
published the letter in the February number of the ‘ Gardener's 
Monthly”), that during a recent dry season he was enabled to dig 
to the very bottom of his peat bed, or “ muck hole,” some six or 
seven feet below the surface. Under the peat he found “what 
appeared to be the bottom [shore] of a lake, showing clear sand, 
gravel, and small shells, exactly like the shores of the lakes so 
common in this country. Imbedded in this gravel we found a 
boulder, and around it were charred sticks, looking to all appear- 
ances like the remains of a camp fire, and near it we found sev- 
eral poles that had evidently been pointed at the thickest end 
with an instrament not very sharp, proving, at least to my satis- 
faction, that Indians had camped there, and that the 
saplings were their tent poles cut with a stone hatchet. While 
digging last summer about three rods from the spot named, we 
