Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1876-08-09
MECHANICAL AND SCIENTIFIC.

If people were to shut up and
darken their houses in the coolest
hours of the morning, leaving only
apertures enough for ventilation, and
to those apertures apply, as folks in
India do, loosely-woyen mats of fra
grant grass, and keep them wet, every
breath of air coming into the house
would take up the moisture, and the
temperature within would be reduced
many degrees. --ETchanye.
Thin sheets of copper secured to
the inside of locomotive boiler, and
forming an internal skin next the
water, have been tried with some sue
cess in Austria. The engine ran a.
900 miles, and was then examined
The copper was found to be only
slightly encrusted, and the iron plates
were perfectly bright and clean. 1t is
estimated by the builder that the life
of the boiler may, by this means, be
extended more than double its usual
limit.
The fuel Of the future in the
varied manipulation Of the rolling mill
will, according to the Ameyic03l Md11,b-
tdctuyer, undoubtedly be gas. In a
highly interesting discussion of this
important scientific and industrial
question, in the journal named, it is
also argued that the great point now
waiting to be clucidated, in this con
nection, is the form of furnace which
will be used. For the present, at
least, in old works, and especially
where bituminous coal can be procured
at a low figure, the cost of gas furnaces
viii stand in the way of their intro
duction. In such works the aim will
be, of course, to devise some method
by which the old furnaces can be used
with little OF no alteration.
Experiments show that the weight
which carriage wheels are calculated
to bear is governed by the circumfer-
ence of the spoke, measured at half
way its length. Thus a spoke whose
circumference at half way its length is
three inches, will carry nine cwt. /; BIB
equals 8, SO of any other diameter. \
spoke 24x2a equals ~ expressed in
centals. BY this formula, the weight
which any carriage wheel is able to
bear safely may be readily calculated.
II is further ascertalned by means of
this simple rule, that Il four wheeled
wagon. travelling at the rate of three
to four miles per hour, Will carry the
full square of the circumference of the
spoke of its wheel in cwts., over and
above its own weight; a cart half the
square. \ carriage travelling from six
TO ten miles an hour will carry the
square of its spokes i'll cwts. of car
riages and load; a gig half this. ".
Y. sun.
The common butterfly called the
Painted Lady, or I0neSsa C0yr'ui, is
an inhabitant of al the countries lying
within the Temperate and Tropical
Zones, with the exception Of the Con-
tiuent of South America, and the
small islands lying east and west of
North America. In fact, ii is the only
member of its tribe that can be prop
erly termed a cosmOp0litc, 1t has
been the custom of naturalistS to con-
slider the Old World rs the primary
home of the species; but Mr.. :. II.
Ncudder brings forward the theory. in
the Naturalist. that il had its origin
in the New World, Thepresence of
| the insect ON the shores of Behring'
straits as testified 10y Wagner is
saws Mr.. Scuddcr Ian indication OF
its route from America to Asia; and
| this passage must have taken place in
/ times 50 far distant that it has had op.
! portuuity 10 push its way to Australia
and New Zealand, and there to become
So modified us 10 establish a peculiar
race. once digniied 10y specific name. -
4 Faithful Cashier.