The Mankato free press. [volume] (Mankato, Blue Earth County, Minn.) 1879-1924, 1886-03-05
SCIENTIFIC MISCELLANY.

In n late paper read before the Scotch
Institution of Engineer. Mr.. Peter
Carmichael stated that all qualities of
iron became hard and brittle after SER
vice in boilers for more than dozen
years, especially where exposed directly
10 the fire. In the furnaces even the
best iron becomes as brittle as common
iron i'm that time. and great care has to
be taken in making repairs to prevent
The plates from cracking. For this rGa-
son sixteen or seventeen wears is long
enough for boiler TO b. in use. at II
pressure OF forty to foriy-iiyr pounds. II
nscd longer the pressure ought 10 be
lowered. In two boilers which had
been used nineteen years even the rivcts
were so brittle that their heads blew of
OH being struck.
A new American process for rapidly
drying timber, hides. wool, grain, and
other substances surchargGd with m0is-
ture. has been attracting considerable
attention in England. 1t is called the
cOol-dry air process, and consists IN
passing through the chamber containing
the moisturc-laden material u conlin-
uous current Of furnace-dricd air having
a temperature between so and 80 de-
grees Fahrenheit. The moisture is alb
sorbed by the air in So remarkable n
manner that oak logs are reported to
have been finished In nine days, al
though natural drying would have re-
CURED three or tour years, The tenn
pcralure is so moderate that delicate
iibres, fabrics and chemicals are not in
jured.
From English mortality statistics eX-
tending over considerable period, Dr.
William Ogle finds that the death-rate
among clergymen is lower than that in
any other occupation. If the mortality
for the three years 1S80-S2 among min
listers be represented by $50, that among
farmers will be denoted by 63l, among
lawyers by S4l, and physicians by 1922.
The high mortality rate among the doc
| tors is "A source Of alarm to an eminent
medical authority, and is regarded as
demanding the most thorough inveSti-
CATION.
A noticeable feature in the climate OF
southeastern India. according to Col. b.
K. Branlill of the London Geographical
Society, is the frequent lightning storms,
which occur da ~ for weeks together,
before the setting in of the southwest
monsoon. maccompanied 10y rain or by
any sound of thunder, This curious
phenomenon is most frequent in dis
trictS where land and sea brcczcs alter
nate with much regularity.
A German physician has experiment.
cd 10 ascertain the hour of the day nj
which man is ut his best and able Ia
DO the most work with the least fatigue,
and has concluded that hr is strongest
at the time of rising He has shown,
also. that breakfast has IN important
effect on the muscular powers, and
urges early eating for those who rise
early.
A new illuminating agent, which N
eminent Russian chemist predicts will
succeed kerosene. has been tried in ST
Petersburg. 1t is called pyronaphtha
and is prepared from the waste pro
duets OF the Baku distillation of petrol
cum. 1t burns with bright light
without smoke or vapor. and is no
liable 10 take fire accidentally or 10 cX
plode.
An eminent German oculist, DIR. III
Cohn. has made extensive researche
into the effects of study and microscope
labor on the eyes, and he conclude
that reading and writing are much NOR
likely to produce short-sightcdneSS an'
otherwise impair the sight than watch
making and other minute industries.
The New Zealand government is seek
ing to promote scientific mining b.
sending competent lecturers to TIN
various mining districts. The lecture
are well attended.
The singular report is made by tw'
French experimenters that silicon
though unaffected by Il temperature @
1870 degrees Fahrenheit, vo!ati2as Il
S2l degrees.
A garnet crystal weighing nine and
half pounds was lately found eight fee
below the surface of "a New York street