ng the manners of a much later age. It is formed of the
military weapons, bridges, fortifications, camps, etc., which were
constructed to illustrate the "life of Caesar," by Napoleon. This
collection is, and will probably remain, unique. At the meeting of the
Geographical Congress last year, these great engines of war were taken
to the park and exhibited in action. The museum is now placed under the
control of the historical commission for constructing the map of Gaul.
This body is publishing a series of maps and engravings to illustrate
the progress of the science of the prehistoric and subsequent periods. A
catalogue of the collections has been made and is sold to visitors.
There is also in the establishment a special library in which has been
collected by M. Gabriel de Mortillet all the books relating to
prehistoric antiquities, and which is open free on certain days to the
public.

* * * * *

It is found that insects preserve their colors better under yellow glass
than in any other color. The curtains of entomological show-cases and
the blinds of the room should be yellow. Only in this way can the
delicate carmine tints of some insect wings be preserved.

A student of animal nature announces a case of two hens, who by joint
efforts hatched one chick. They have since, for some weeks, been
parading the yard, each clucking and manifesting all the anxiety and
care of a true mother over this one. The hens never quarrel, or show the
least appearance of jealousy or rivalry.

M. Tresca, who has charge of the Conservatoire des Arts et Metiers, the
institution which in Paris answers to our Patent Office, says that
drawings of new inventions are more useful than models, are cheaper, and
are very much oftener consulted. In Paris the model room is covered with
dust and rarely entered.

The French weather bureau intends not only to study the thunderstorm,
hailstorm, rainfall, inundations, and frosts, with especial reference to
their effects upon agriculture, but also to experiment upon the
asserted effect of smoke as a preventive to frost. The experiments will
be extensive and may cover a large valley.

To discover by the spectroscope the smallest quantity of a gaseous or
very volatile hydrocarbon, the Messrs. Negri introduce a small quantity
of the gaseous mixture into a tube. This mixture should not contain
oxygen, carbonic oxide, or carbonic acid; and the pressure is to be
reduced