Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1881-01-27
POPULAR SCIENCE.

By the use OF sand aud sulphur, with
ar addition of Is per cent. manganese,
the ancient black gloss of y Venetians
is so closely initiated, tits said, astodeiy
detection.
To COLOR or dye small pieces OF ivory
black, wash well with an aqueous solu-
ton of neutral nitrate of silver. Ex-
pose to sunlight--under glass until
black. Repeat, II necessary, until the
proper color is developed.
AN inventor thinks he has solved the
problem Of propelling boats in canals
and rivers by means of eiecting water
from the boat. Unlike his predecessors,
he makes use not of large pipe, but OF
a great number of tubes with very small
outlets.
THE distance between New York and
Philadelphia, in an air line, is 81 miles,
over q comparatively level country. In
d paper before the Franklin Institute,
Mr.. w. Barnet lie Van maintained that
an airline road could be constructed
between the two cities, on which trains
could make the distance IN one hour,
and that the enterprise would pay. The
line he proposed would cross no roads at
grade. ana would have but two curves, OF
10000 feet radius each.
me tests of the durability Of steel
rails on the Great Northern line of
England show that the hardest rails do
not wear the best. In one instance a
hard rail was worn away one sixteenth
of an inch by traffic amounting TO
1851, 600 tons. A softer rail near by
was worn the same amount by s, 402, 005
tons. In another instance the total was
is, 53l, 900 tons for hard rail, md 81, :
O6l 900 for soft rail, the wear and tear
being the ame--one-sixteenth part Of
an inch. Analysis she wed this last rail
10 consist of So ATS per cert. Of iron and
minute quantities Of carbon, phospho-
rus. silicon, manganese, sulphur and
copper.
ATTEMPT has been made to propel
boats on canals and rivers by conduct
ing d column of water through pipe
and eieeting it forcibly at the stern, but
it did not prove successful. An English
man now claims to have got over the
difficulty by showing that 'tthe FORE ex-
cfted by one fluid pouring into or against
another depends on the contact of sur
faces. and not on the sectional area of
the flowing mass, alter the flowing mass
be once set in motion. Instead, there
fore, of tubes with large oritices, he
makes use of tubes with marrow outlets,
mere slit. and thus obtains a large
superficial contact by ejecting water
through a series of narrow openings.
WHmE DR.. Charles Roberts, in paper
on the hereditary transmission of physi-
cal and mental qualities, is at loss to
say how ''sigor' may be utilized, he
makes bold oash at the solution If the
problem. lie IL very decidedly of the
opinion that persons living under very
similar conditions of life should not
marry. "A literary man should not
marry literary woman, nor a tailor q
mistress; and the rule should apply to
persons Of the same temperament and
physiques. The immense trouble, so to
speak, which nature has taken to secure
Decentralization in the lower races of
animals and plants should guide man in
his selection of partner. The evils
arising, or, better, transmitted or inten-
sified, from the union of persons under
like conditions of life are very similar to
those which spring from the marriage of
men and women closely related by
blood.