Washington standard. [volume] (Olympia, Wash. Territory) 1860-1921, 1861-07-13

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down to 1900, exhibited beggarly dis
play of tallow candles. In 1784, Ar
gand. of Genoa, first introduced his
burner, which was the only correctly
composed lamp with large fame, the
peculiarly of which consisted in having
a hollow wick, thereby enabling cur-
rent Of atmospheric air to reach the ih-
side rs we'll as tho outside of the fame.
Since that period, the Argand lamp has
been used in all lighthouses, until
within a comparatively recent date.
The research Of Arago and Augustin
Fesncl, acting as associates, produced
the burner with two, three, four and
five concentric hollow wicks, with all
air current passing up through each Of
the open ring-like tubes or spaces be-
tween the wicks. The effect of this
invention has been to gather the previ:
Gus cluster of separate lamps, formerly
used, into single central lamp Of decid-
edly greater power. One Of these
lamps Of the first order, with burner
composed of four or five conccntric
wicks, producing flame four to four
and a half inches high and four and n
half inches in diameter, the wlcks being
one. fourth of an inch high, will con-
sumo about six-sevenths of quart of
oil hourly, and will servo the purpose
of all ordinary demands Of the highest
tower for the limit Of range prescribed
by the earth's sphcricality. The me-
cbanical part Of this light-generating
problem has reference chiefly to main
tain II continuous flow or supply of the
oil over the wicks of abolt five times
the amount Of oil burned, which serves
to prevent the charring Of the wiclSs,
and obviates the need of frequent
trimming and raising. The surplus is
caught in a dirper, strained and again
uscd." In the French Description ees
IMachines areinnumcrablc specifications
for burners, oil cisterns, oil pumps,
oil pump valves, lamp regulators, oil
supply alarms, etc., and the main result
is that there are now in use in light
houses the clock-work movement, the
Wagner lamp, Lcplantcs lamp, the hy-
draolic pump and thcpncumatic pump.
At Tatoochc light the clock-work
movement is.uscd. There is also n.y.
draulic pump, but is laid aside. But
the main feature of a Frcsnel light is
the lens, or optical portion. If wccon-
ceive simple naked light burning on
the summit of tower or hcadland, the
rays would issue in all directions from
the flame as centre, but only those
portions that proceed in a dire ction to
meet tho navigator's eye could be Of
any service. 1t is, therefore desider.
atum so to collect those rays within the
limit of useful effect that they may ex-
ert their whole power go as to produce
a light that shall just fall upon or over
the water within a section drawn around
the light and limited to the extreme
radii passing over navigable areas.
In 1919, Arago offered to undertake
for the French lighthouse commission,
q series Of systematic research, aud to
assist him Fresncl was detailed as an
officer of Points ct Ckausses, who at
once commenced tho train Of brilliant
research that has ventuatedin produc-
ing the most perfect lens ever yet in
use in lighthouses
The form Of tho lens.is ~ follows:
Around the central lamp fame Of con.
centric wicks are arranged, for a
fixed light Of the first order, Il Tatooche
light.) horizontal hoops or rings Of
glass, 20 shaped aud placed - to throw
out in a horizontal direction oil the
light received on them. Thus while
all the horisontal rays are thrown to
their fullest extent, the vertical rays ars
b,ought down into fat horisoutalism,
(as when chestnut:burr i preased 1at,)
and the illuminatiop j. equally didussd
over al points in tho horison. Tho
middle ring a the level AZ the 1ams b
| 4 plauo-eonvs o. considerable width
above and below the focal lsvsl, and
abovs and hslow this ars asrsngsd'fhs