The mirror. (Stillwater, Minn.) 1894-1925, 1917-11-29


course will be published only initials of each querist
being used (Ed)
Q:-Kindly let know the of Lakes Superior,
Michigan, Huron. Erie and Ontariol &C. K.
A-Lake Superior 200 square miles, Lake
Michigan 0OO Lake Huron $780, Lake Erie $500 and
Lake Ontario 7,24O.
Q:-What the sign denoting pounds of the English
money what the equivalent value American gold
the English pound? IS. c. o.
A:-.The character ''9 is from the old English black
letter "L,'' abbrevston Libra-a pound weight
Ancienty the pound money by law pound weight of
pound is 81. 1865.
O-When was gun powder invented &C. r.
Alt is said have been first used in Europe March 49,
$780, the Veneans against the Genoes The discovery of
powder attributed Berthold Schwartz, monk of Mayenc
about 1900 A. d. though said have been known in
India very early and obtained from that country by Aaians
who employed it in battle Mecca in $50.
o:-when the first Thanksgiving Day celebrated
A:-February d. 1880, in Massachusetts, had been ap-
pointed for general fast No ship had arrived great length
and provisions nearly exhausted. AT this critical
vessel arrived from England with provisions and the
day Immediately turned from public fast public
feast The festival of Thanksgiving celebrated really
Der 1920 the date they anchor Cape Cod Each
thereafter day in November observed give thanks
God for bountul havests and safety from the avages
O:-Will you kindly advise writer whether it
ever rains in the lower Nile River Valley in Egyp-J c.
A:-At Alexandria along Mediterranean Coast of
Egypt winter The average yearly rainfall is
about eight inches At Cairo rainfall is irregular and
be due occasional rather than to rainy
However falls in the winter months, January
lad IN nd Tu1
The average does exceed inch and half In the
desert heavy burst from time time causing sudden
floods and drowning and animals in the ravnes
These frequent the regions of the
Sinai peninsula.
o-Can photographs be telegraphed, and if so, how'
&C. w.
A:-Yes. Teephotography depends upon selenium's
peculiar property being in the dark but
light strikes it. The original in the form of
Photographic negative wound glass cylinder The light
from Nerns electric lamp concentrated to point by lens
and focused picture totally rejecting prism, placed
glass cylinder projects the light through the film to
seenum cell situated the end of the cylinder The point
of light travels by mte the surface of the film
the cylinder slowly vo and the prism which
shoots the seenium CELL As the dark spots interrupt
the light the light shadow of picture thrown inch
BY inch enium CELL which, intensely sensitive light
electric varying with the quantity of light
that hits it.
At the station cylinder, covered Win
Photographic film revolve unison with the transmitting
Upon this film pencil light from Nenst lamp
traed which off from the film when the seenium cell
at the other sends current while shutter
admits light film when there is current and admits
proportonay the strength of the Thus photo
graph may be reproduced perfectly over distance
Q:-Please solve following problem and oblge.
(a) mechanical efficiency of engine IS cent,
and the efficiency generator that coupled this engine
% per cent? if this $500 klowa what is the
indicated H. co. What is the shaft H. p this output?
fc If this unit requires IS b of steam per kowatt hour
what is the water per indicated H. Pr c.
A-One XVI "a electric power measured the
switchboard which evidently shaft brake output less losses
in the generator the efficiency of the "a
cent the brake horse power d. H. P of the engine will be
equal to the divided by Inn consequently
134x $500 : 3563. SO: and since YOU say tina.
B. =: ~; ~ the HI 10 05576 "a 375l4
YOU give however, the consumption per !. H. p in
XVIII, therefore, 1. H. P xo94 15 approx
| imately
Steam per XVIII then, divided by LIS will give the
or water rate per H. P. per Hr, which in this will be
| 151.5=10.
The complete answers, therefor (a) 37514 l. H. r.
(b) 1858 83 B. H. P. (c) 10 Tbs. per H. r per Hr.
total of consumed by the unit IN one
hour would be ~ 31214 rs 45l65 gallons approx
imately-O. c. L.
UNANSWERED QUERIES
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