The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1872-06-28
SCIFNTIFIG NOTES.

The Flow OF LIoUIDs.-ProL Cold
ing gives, in the " Copenhagen
Transactions" his Investigations OF
the law of the motion of water Ia
pipes and conduits, and has also ap-
piled his result to ocean currents.
His method is to determine the no
ton of liquid threads, that motion
varying with the depth when water
flows over a plane surface. The
formulae now generally used are
founded on the assumption that wa
ter moves IN plane layers ut uniform
velocity. These formulae are known
to be defective.
MAMA. .Boussingault has given to
the Paris Academy OF Lcience an ae-
count of his observations on man
ma obtained from the leaves taken
from near the top of an old linden,
In the Vosges. Other trees OF the
same kind in the vicinity yielded no
mamma. The composition of this
mama was found to be about 55 per
cent. of cane sugar, 25 of glucose,
and 20 of dextren. The mama from
Mt. Sinai, examined by Ehrenberg
and Berthelot, has nearly the same
composition, and was supposed to
be an exudation caused by the pune
ture of an insect.
GUxpowDKR GAUaE.-The principle
suggested by Tresca's experiments
on the flow of solid bodies, has been
applied by M. le Commandant de
Reffye to the determination of the
pressure in the bore of large guns.
cylindrical hole, bored into the
gun, is filed by block of lead, sup
ported behind by a steel block,
through which is a small cylindrical
hole. When pressure acts on the
lead, a portion of it is forced into
the hole in the steel block. The vol
ume of lead found in the cylindrical
cavity after the gun has been fired is
the measure Of the pressure IN the
bore of the gun.
MINERAL CoTToN.-Mr. Coleman
Sellers, of Philadelphia, exhibited,
at recent meeting of the Franklin
Institute, a sample of a product
formed by allowing a Jet Of steam TO
escape through a stream of liquid
Stag, by which the Stag is blown into
the finest threads, sometimes two or
three feet in length. These threads
of glass readily break up into much
shorter ones, which, being white,
somewhat resemble cotton-hence
| the name. The material Is slow
| conductor of heat, and as great guam
titles of air must be retained IN its
insj erstices, it is well adapted to
many purposes where so-called non
conductors of heat are required.
BEssEMFR's GUN.-In the improved
plan for heavy ordinance by Mr.
Bessemer, the initial pressure is re-
duced by having a series of smaller
charges ignited successively rs the
shot travels along the bore of the
gun. This is, however, the essential
feature of the American gun patent
ed by Mr.. a. S. Lyman. In order
| to secure the greatest benefits from
this method of applying force Mr.
Bessemer proposes to increase the
length of the gun to fifty feet. 1t is
to be made of wrought-iron tubes,
connected by fanges and strengthen
ed by steel rings. Rotation Is to be
given to an elongated shot, not by
rifing the bore of the gun, but by
the reaction of powder gas issuing
in small jets through tangential ORR
fees at the circum ference of the shot.
The shot is to be made hollow, y nd
contain the charges of powder re-
quired to rotate it. The objections
TO Mr.. Bessemer's "improvements"
are so grave that it may be doubted
whether he will carry them into
practice.
The Declaration of Principles
adopted by the Free Christian
Church Of Italy" which Father Ga
vazzi now represents in this country
contains what is considered a sound
orthodox creed. An Old School
Presbyterian and a Methodist can
accept it with equal heartiness. The
Independence of each church in local
affairs is Congregational. all, how
ever, combined into General Az
sembly.