The Washington times., 1921-05-22

The entire scientific world today is<
mourning the death of Doctor Rosa
A seeker after the truth In science
and an interchangeable worker In the
interest of things electrical. his death
is = shock to . host OF friends ana
admirers.
Doctor Rosa was q native OF Rog-
ersville, N. Y. He was born Decem-
Der 4, 1861. tho son Of the Rev. Ed
ward d. and Sarah @. Rosa. He was
educated for his life work At Wes-
ieyan and Johns Hopkins universities
Tor q short time he was Instructor
OF the University Of Wisconsin. leav-
ing there to become professor OF
physics at Wesleyan. In 1901 he be-
came chief physicist at the Bureau OF
Standards.
WAS FOOD ExPBRr.
At Wesleyan University Doctor
Rosa developed the physical side OF
the respiration oAloPimeter with Prof.
w. o. Atwater. This apparatus was
Of great value In tho pioneer inves-
t,gations on the value of foods and
the study Of nutrition prebisma
He took . leading part In the re-
searches to establish the fundamental
electrical unit after coming to the
Bureau Of Standards and served rs
ScCE0t6Iy VI NH0 XhtCIu1IiOuAi SOui~
n:ittee on Electrical Units and Stand
ards. He developed the electrical
work Of the Bureau of Standards
from . small beginning to IN organ
ization covering the scientific and en-
cheering aspects Of . great national
laboratory.
When DR.. Rosa took charge Of the
electrical division Of the Bureau of
Standards. In addition to the general
supervision Of the work of the divis-
ion. he took active charge Of the sec
ton on inductance and capacity and
absolute measurements. AS the work
of the electrical division grew, 1t was
necessary for him to relinQuish some
Of the detailed work Of the section.
However, he remained in active charge
Of tho section until the division moved
into the electrical building in 1915.
When Of. Rosa began his work in
the electrical division. 1t was his am
bition to determine . number Of the
fundamental electrical constants In
conjunction with DR.. Dorsey he i'm
m mediately undertook the determine
tion OF the ratio Of the electromag-
netic and electrostatic units. The re-
suits obtained are the most accurate
which have ever been determined.
SPENT YEARS IN RESEARCH.
About LOOT DR.. Rosa and Dr. Dor
sey started their work on the determ-
ination of the ampere. This work ran
over . period OF years, and gave a
value Of the ampere which had not
previously been equaled In order
to be able to reproduce the ampere in
q concrete way, DR.. Rosa and Mr..
Vinal started work on the silver vol
tameter. This was carried on stimuli
with the absolute determi-
nation of the ampere so that now we
are able to define the ampere in q
satisfactory. manner.
Doctor Rosa devised . new ap-
paratus for determining the absolute
were tried in 1908 and 1900, and gave
promise Of satisfactory results. How
ever, the pressure Of other work COM
pelled the abandonment of this ex-
pertinent, but he had always hoped
that the time would soon como when
1t might be continued.
Doctor Rosa found that the
formulae for the computing of in
ductance were not well developed and
were scattered widely through the
literature. He undertook to collect
these formulae together and In doing
SO, found 1t desirable to considerably
early years at the bureau he pub
lished a large number of papers on
the computing of inductance. Finally.
in connection with Doctor Grover, he
collected together practically all the
known formulae for computing in
ductance. This collection Is known
the world over as being a model of its
kind
PERFECTED WAR INVENTION.
In 1910 there was instituted under
DR.. Rosa's direction an exhaustive in
into the subject OF cleo
trolytic corrosion of underground gas
and water pipes. and lead cable
sheaths due to stray currents from
electric railways. This problem hao
for years been one of major import
ance to public utility companies
throughout the country. and prior to
the work being taken up under DR..
Rosa's direction at the Bureau Of
very little definite Informs
ton was available as to the laws
governing electrolytic corrosion or
the methods Of reducing the trouble
from this source. The work done
under his direction included a definite
establishment of laws governing cleo
trolytic corrosion, and much progress
in the direction Of mitigating trouble
Of this nature. This work has for al
number Of years been carried on In
close cooperation with the utility
interests of the country through the
medium Of the American committee
on electrolysis, of which DR.. Rosa
was a member.
During the war DR.. Rosa directed
the, development Of number OF scien-
tihc instruments which were OF in
estimable value to the American
forces in France. Among these might
be mentioned a sound-ranginR device
for locating big guns. the seophone
for the detection Of mining operations.
the development of aircraft radio ap-
paratus, and the Improvement OF
radio direction finders by which
enemy ships and aircraft could be. To-
Gated. Under his direction at the
Bureau Of Standards was established.
perhaps the finest radio research
laboratory in the country. and no has
always shown an intense interest in
improving apparatus and methods OF
radio communication.
INVENTED SAFETY CODE.