New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-08-23
APPLIED SCIENCE.

TIM VELOCITY or TRANSMISSION OF MAdSETlM.
I'm order to remove all doubt as to the accuracy OF
che results of preceding investigators DR.. Herwig
has sought to determine the velocity OF transmission
Of magnetic influences by separating the various por
hons of his apparatus to very considerable as
tauce. and he concludes that if the action of the
terrestrial magnetism really possess aehn.e ws,o
sity il NEST amount to al least hall miinoh nhieS
per second or in other words that the terrestrial
magnetic influence makes itself felt at any point OF
The earths surface in less than one three-hundreth
If . second.
SOLAR SPoTs.-Gauthier states that as the result
3t2 years of observations on the solar phenomena
Nv means of the equatorial of the observatory at
Geneva. kindly put at his disposition by Prof Plan
amour, he finds himself entirely justified in coincd-
ma perfectly with the theory of Zolner as to
,olsr spcts being scorie floating upon the lqnid.
md possibly even within the denser gaseous portion
d the solar surface They apparently the result
cooling depending on the TaaCn by S %5 Se Is
The only one that seems TO him not TO contradict
both ordinary laws of physics and well-known facts'
DIFFERENTIATION OF OZONE IN THE AIR.-The de-
termination of the quantity of ozone in the air has
sot yet been achieved by any convenient method,
n<e the tint Of the ordinary test papers IS de-
ermined BY the velocity of the wind. 1t was sup
,oscl by Won Pettenkofer that the absence OF The
,zoue reaction in the atmosphere OF closed dweDng-
rooms due to the slight CIRCULATION IN me ar
This subject has however, been fully investigated
hy Wolfhugc who finds that, while gwen guam
tity OF fresh air yields very visible ozone reaction
yet 10 or II times that Quantity sasen vd o b .e the
rooms are unused, having previously DSen Ven
aired Wolflmigel has also shown that there Is
great absence OF ozone in the ar near INC gioun-
IMPROVEMENT IN SPECTRosCOpEs.-Mr. MADAM
gives a simple method by which we may correct the
curvature of the spectrum lines, defect inherent
IN all spectroscopes as at present made. This ao-
,orrtiop is due TO the fact that the rays from dif
ferent parts of the prism fall the prism under dif
fereat vertical angles. Mr. Grubb has lately pro-
posed TO correct the curvature by method wmch
had been already employed by Mr. MADAM for more
than wear past and which consists in making the
et itself curved instead of straight, the curvature
being so arranged as 10 neutralzc the dlstortlng
. effect OF the prism. Mr. Madans experience shows
that the curved Sits give perfectly Sgap,ed c a iS
spectroscope that BY having several shcn snts
in succession, inav secure stralght mes III Inc
field Of view for varying powers OF dispersion. lie
finds that Sits whose edges curved 10 a radllS
of 21 ceniimceTs, sensiby correct the distortion OF
siage carbon c 5sSpphde psT l 'He bosc radns Is
10 centneters eorreets the distortion o1 tram OF
two such prisins.
AMERICAN MINING NETHODs.-One Of our Com
stock mining engineers lately returned from tour
of inspection through the mining districts of Ger
mauy, communicates TO California daily his con-
vction that there is 10 engineering IN Germany 10
compare with that on the Comstock lode, ana no
mines in which the mechanical appliances arc so IN
genors and effective. lie supports this assertion by
q graphic description of the crude. and primitive
methods in vogue abroad. He remarks that in the
deep mines Of Bohemia the hosting apparatus con-
sisted merely of open tubs and the operating ma
ehinery was so poorly constructed that he dared not
venture TO descend. In most of the German Mines
lie found that the were compelled TO walk III or
down TO the scene Of their abors, either by going
down an incline, or by using long parallel Suits
which move up and down alternately about SIX feet
s o time The mode of ascending and descending
on these is TO step from to the other, rs each
ascends or descends where n misstep would be at
tended with fatal consequences. His remark that IN
the Comstock the men went down to the lowest
levels and came up in two minutes without the
slightest exertoD, received politely but incredl,
lously The character of the mining tools employed
j. criticised in the same uncomphmentuy STRAIN,
and the assertion is made that an average days
work upon the Comstock would seem incredible to
the miners of Continental Europe.