Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1891-01-10

Lam Augustus Rogers, who was born in
Waterford Conn in November ls32.
After studying a TIE seademie- "a De
Rlyter and Alfred. y y. he entered the
sophomore class at Brown university, and
was graduated there Ia 1851.
Returning % Alfred. he began b work
a. a teacEer there. and 10 l'51 he was
chosen professor e mathematics and as
tr0uomy at the academy. where BE- then
remained t1T thirteen Fear-. Meanwhile
from t5me % time. BE- studied as the Shelf
field scientific school, Al the Harvard OBJ
seEyat0ry, and during the civil war for
fourteen months be served IN the United
States naval SER Ice. 10 1870 ne became
an assistant In the Harvard observatory,
and IN 1871 was made assistant professor
OF astronomy there. TINS place be held
uutli l.s6. when be Jgned 70 accept the
chair OF astronomy ana physics Al Colby
university, ha..rviAe, Ne, which he
still retains
While at Alfred be Superintendent the
bui3ln. Of the observatory there. and ar
ranged tor IT. equipment; while at Har-
ward nIs specLa- work consisted IN J5serg-
ing and mapping AL the stars down % the
degrees. located a little north OF oar zenith.
This work has been done under the aus
plces II the German Astronomical s0CI-
ETY., IF which be- Is a member -Four or
I've Volume. If these obs Yati0us have ale
ready been issued, aod others are in pep
arau0n
His special reputation, however. has
been maze ia mlcr1metEy. One Of the
first difficulties that be met with In bis
work was the lHaiugo micT0metar spider
webs that were suitable for his purpose
De hen began series Of experiments IN
order 10 fad practical method Of etching
lines on giJSs. After many frultless ef-
forts, the desired result was obtained by
making a t.m on the glass, cutting the
lines 70 be etched through this finn by
means Of a still point. and exposing the
plate thus prepared 20 the fumes of hydro
Hu1rIc acid confined In a close vessel at
the particular point Of time when tine
fumes contained the proper degrees OF
moisture 70 give them the maximum ethcl-
ency.
The success was 20 complete that he Sc
cured an order from the United States gov
ernment for the plates which were used by
the expeditions that were sent out from
this country 70 observe the two transits Of
Venus. F0rupward Of sixteen wears be
has closely studied this subject, and his
knowledge Of 1t has made MIN the uniyers-
ally acknowledged authority IN all THAI per
talns 10 Iuecrometrlcal work
Professor Rogers has also made a speci-
atty Of the construction Of comparators for
the determination Of differences in
lengths, thus establishing useful working
standards Of measurements for practical
nat ehanjc8l work. This research resulted
in tie R0g, s-Boud universal cOmparat0r.
built by the Pratt & Whitney company. OF
Hartford, who were thus enabled 10 estab-
llsh their system of standard gauges In
1850, be was sent abroad at the expense
Of the American Academy Of Arts and
Sciences 20 obtain authorized copie. Of
the English ANA French standards Of
length. These were used as the basis Of
for the bars that he construct.
Ell. and which now serve as standards Of
Of length for Harvard, Yale, C0umbea,
Princeton, the United States signal SER
vice bureau, the Lick observatory and 9TH
ar institutions
Besides other investigations of practical
value Professor Rogers deserves credit for
u4- MtlfHMelef rulings, MhQe both on
glass and metal which are especially APP
preglated Uy mIcroscopsists for the lccu.
racy .as regards division and also the
character and beauty II the lines.
The degree of A. NJ. was conferred upon
him by Ia.ein 1876. and be received that
81 Pm. D from Alfred Ia 1856 He was
9f tine American Association
Tor the Advancement Of Science IN 1853.
presiding over the section on mathematics
and astronomy, au5iu 1856 was president
lf The American Society IF Micr6scopists.
BE TJs elected 10 the National Academy
II Science I,' lS-5.