geodesies are the great circles; every mariner or aeronaut who
desires to sail the shortest course between two points sails along
a great circle. To take a definite instance, the shortest course
from Panama to Ceylon is not along the parallel of lat. (about
9 N.) which joins them the aeronaut wishing to fly the shortest
course between the two countries will fly N.E. from Panama,
he will pass over England and finally reach Ceylon from the
north-west. The reader may rapidly verify this by stretching
a thread tightly over the surface of an ordinary geographical
globe. Let him now trace out the course on an ordinary Mercator
chart, and it will be found to appear very curved indeed the
course of the aeronaut will look surprisingly like that of a comet
describing an orbit under the attraction of a sun situated
somewhere near the middle of the Sahara.
The reader who performs these simple experiments will
understand how Einstein was led to suppose that gravitation
could be explained by a curvature inherent in the continuum.
The world lines of particles are geodesies but the space itself,
so to speak, provides the curvature. The curvature of path is
thrust upon the particle by the nature of the continuum, but
we, who until recently have been unaware even of the existence
of the continuum, have been tempted to ascribe it to the action
of a special agency which we have invented ad hoc and called
" gravitation." According to Einstein, it is no more accurate to
say that the earth attracts the moon than to say that the pockets
of an uneven billiard table repel the balls.
This train of thought may seem artificial. If so, the reason
is that we have not been able to explore the other possibilities
which have branched off our main line of thought. In point of
fact, Einstein found himself practically limited to the conclusion
we have stated. Not only so, but the actual type and degree of
curvature in the continuum prove to be uniquely fixed in terms of
the masses of the gravitating bodies. Thus Einstein, knowing
the mass of the sun, found himself in a position to predict
absolutely what the motion of the perihelion of Mercury ought
RENEVIER RENNENKAMPF
267
to be. It was found to be 42-9" a century, a figure which agreed
with observation to well within the limits of error of these
observations. The motions of the other planets, as predicted
by the theory of relativity, have also been found to agree with
those observed to within the errors of observation. This latter
test, however, is not a very stringent one, since the departures
from the motion predicted by the Newtonian law are too small
to admit of very precise measurement.
Einstein's theory requires us to suppose that the world line
of a ray of light also shall be a geodesic in the continuum. In
a gravitational field the curvature of the continuum will impose
a twist on the path of a ray of light. Einstein found in particular
that a ray of light which comes from a distant star and passes
near the edge of the sun on its journey ought to be bent, in its
passage past the sun, by an angle which should be 1-75" if
the ray just grazes the sun, and would be less in proportion to
the inverse distance from the centre of the sun for other rays.
The observatories of Greenwich and Cambridge dispatched
expeditions to test this prediction at the eclipse of 1919. It was
found that the stars which appeared near to the sun at the
instant of eclipse showed an appreciable displacement, as
compared with their normal positions, of the type required by
Einstein's theory. Exact measurement confirmed that the dis-
placement varied approximately as the inverse distance from the
sun, and that the displacement at the limb was sensibly equal to
Einstein's predicted value of 1-75". The Cambridge observers,
hampered by cloudy weather, obtained for this quantity the
value 1-61" =*= 0-30". The Greenwich observers obtained a
value of 1-98" =t 0-12", but it has sincebeen pointed out by
Prof. II. N. Russell that their photographs indicate a horizontal
and vertical scale difference of the order of i part in 12,000,
almost certainly due to a distortion of the coelostat mirror
under the sun's rays, and if the measures are corrected for this
the result is brought much closer to the theoretical prediction.
The theory makes one further prediction which admits of
experimental test. The atoms of any element, say calcium, may
be supposed to be formed according to a definite specification,
the terms of which depend neither on the velocity of a particular
observer nor on his position relative to the gravitational fields
of the universe. It can be deduced that the light received from
a calcium atom situated in the intense gravitational field near
the sun's surface ought to be of slower period, and therefore of
redder colour, than the similar light emitted by terrestrial atoms.
To be more precise, the Fraunhofer lines in the solar spectrum
ought to show a displacement to the red; this displacement
ought to be homologous, and should be of amount 0-008 A
units at the cyanogen band X 3883 at which observations
have been chiefly made. Attempts to test this prediction led
to strangely discordant results. All observers agreed in finding
some effect of the kind predicted, but its amount was always
less than the predicted amount, varying from almost nil (St. John,
1917) to nearly the full amount to be expected (Evershed, 1918;
Grebe and Bachem, 1919). In 1921 the position with regard to
this test still remained one of great uncertainty and confusion.
It will have been seen that the restricted physical theory of
relativity introduced a revolution into the foundations of
scientific thought by destroying the objectivity of time and
space. The gravitational theory has effected a hardly less
important revolution by destroying our belief in the reality of
gravitation as a " force." The physicist has, however, to deal
with other " forces " besides those of gravitation, and the
question inevitably arises as to whether these too must be
regarded as illusions, arising only from our faulty interpretation
of the special metrical properties of the continuum. Prof. H.
Weyl has pointed out that the continuum imagined by Einstein,
and found to be adequate to explain gravitational phenomena,
is not, in respect of its metrical properties, the most general
type of continuum imaginable. A further generalization is
possible and the new curvatures introduced must of necessity
introduce new apparent forces other than gravitational. Wcyl's
investigation shows that these new forces would have exactly
the properties of the electric and magnetic forces with which we
are familiar. Indeed, the predicted forces coincide so completely
j with known electromagnetic forces that no experimental test of
\ Weyl's theory is possible. Had there been the slightest divergence
between the forces predicted by Weyl and those predicted by
ordinary electromagnetic theory, experiment could have been
i asked to decide between the two, but no such divergence exists.
It may, however, be said that Weyl's theory makes it highly
probable that all forces reduce to nothing more than our sub-
jective interpretations of special properties of the continuum in
which we live our lives.
Finally a thought may be given to the position, under the new
conceptions introduced by the theory of relativity, of the electro-
magnetic aether. At one stage in the history of science there was
a tendency to fill space with aethers, to the extent almost of one
aether for every set of phenomena requiring explanation. That
stage passed, and by the end of the igth century only one aether
received serious consideration, the so-called electromagnetic
aether of Faraday and Maxwell. This aether gave a plausible
mechanical explanation of electrostatic phenomena, although it
was more than doubtful whether it could account for (-he
electromagnetic phenomena from which it took its name, and it
was comparatively certain that it could not account for gravita-
tion. It gave, however, a satisfactory explanation of the prop-
agation of waves of light they were simply waves in the
aether and travelled with an absolute velocity c determined
once and for all by the structure of the aether. On this view it
was quite certain that an observer moving through the aether
with a velocity u would measure the velocity of light travelling
in the same direction as himself as c-u. Relativity teaches that
this velocity is always precisely c, and this in itself disposes of the
aether of Faraday and Maxwell. Whether any new aether will
be devised to replace it remains to be seen, but none appears
to be necessary. Any aether which can be imagined would
appear to depend upon an objective separation of time and
space. Relativity does not deny that such an objective separation
may, in the last resort, really exist, but it shows that no material
phenomena are concerned with such a separation. By a very
slight turn of thought, the primary postulate of relativity may
be expressed in the form that the material world goes on as
thouh no aether existed.
To the relativist the essential background to the picture of
the universe is not the varying agitation of a sea of aether in a
three-dimensional space but a tangle of world lines in a four-
dimensional space. Moreover, it is only the intersection of the
world lines that are important. An intersection at a point in the
continuum represents an event, while the part of a world line
which is free from intersections represents the mere uneventful
existence of a particle or a pulse of light. And so, since our whole
knowledge of the universe is made up of events, it comes about
that the tangle of world lines may be distorted and bent to any
degree we please; so long as the order of the intersections is not
altered, it will still represent the same universe. And so the last
function of the aether, that of providing a scale of absolute
measurements in space, becomes a superfluity. To the physicist
who urges that space measurements without an underlying
aether become meaningless, the relativist can reply that time-
measurements without an underlying " time-aether " are equally
meaningless. A " time-aether " has never been regarded as a
necessity, and the relativist feels that the " space-aether " has
no greater claim to retention. (J. H. JE.)
RENEVIER, EUGENE (1831-1906), Swiss geologist (see
23.98), died at Lausanne May 4 1906.
RENNENKAMPF, PAUL (1854-1918), Russian general, was
born in 1854 and entered the army in 1873. On passing out
of the Academy of the General Staff in 1882, he was appointed
to the General Staff. From 1895 to 1899 he commanded a
regiment and in IQOO he was promoted to the rank of general.
In the war with China in 1900 he distinguished himself by his
resolute action when commanding a column in Manchuria. In
the war with Japan 1904-5 he commanded first a Cossack
division, and later large forces of all arms, and again won dis-
tinction by his energy. From 1905 to 1913 he was a corps
268
RENNER RHODE ISLAND
commander and in 1913 he was appointed to command the
troops of the Vilna Military District. At the beginning of
military operations in Aug. 1914 he commanded the I. Army
which invaded Eastern Prussia. His inaction during the battle
of Tannenberg, where the neighbouring army of Samsonov was
destroyed Aug. 26-29, was a bitter disappointment, and, by
the masses of the people, he was even accused of treachery.
Personally brave, daring in small actions, Rennenkampf, as an
army commander, showed himself in the strategic sphere alter-
nately rash and timid, owing to his inability to grasp the situa-
tion as a whole. At the beginning of 1915 he was recalled from
his duties of army commander, and later, under the pressure
of public indignation, he was dismissed from the service. In
1918 he was killed by the Bolsheviks.
RENNER, KARL (1870- ), Austrian politician, was born
on Dec. 14 1870, the son of a peasant, at Unter-Tannowitz,
Moravia. He studied law at the university of Vienna, occupying
himself especially with questions tof administration, and early
attached himself to the Social Democratic party. He became an
official in the library of the Rcichsrat, and under the pseudonyms
of " Synopticus " and " Rudolf Springer " showed a fertile
literary activity, especially in connexion with the problems of
the Austrian State, whose existence he justified on geographical,
economic and political grounds. On the nationality question
he upheld the so-called "personal autonomy," on the basis
of which the super-national state should develop, and thereby
influenced the programme and tactics of the Social Democratic
party in dealing with it. As a theorist he was reckoned as
one of the leaders of Neo-Marxism. He had been a deputy since
1907 and after the revolution of Oct. 1918 he became state
chancellor of the republic of Austria, headed the Austrian peace
delegation at St. Germain, and took over, after Otto Bauer's
retirement, the Ministry of Foreign Affairs, which he conducted
from the time of the retirement of the Coalition Cabinet in the
summer of 1920 until the new elections in Oct. 1920. His princi-
pal works are: Grundlagen und Entwicklungsziele der oeslcrrcich-
ischen-ungarischen Monarchic (1906); Der Kampf dcr oester-
reichischen Nalionen um den Staat; Marxismus, Krieg und
Internationale.
RENOIR, AUGUSTS (1841-1919), French painter (see 23.101),
died on the Riviera Dec. 3 1919.
REPARATION COMMISSION: see PEACE CONFERENCE; also
31.123 and 246.
REPIN, ILJA JEFIMOVICH (1844-1918), Russian painter
(see 23.105), died at Knokkala, on the Finnish frontier, July 17
1918.
REPPLIER, AGNES (1858- ), American writer, was born
in Philadelphia April i 1858. She was of French extraction
and was educated at the Sacred Heart Convent at Torresdale,
near Philadelphia. She* was one of America's chief representa-
tives of the discursive essay, displaying wide reading and apt
quotation. Her writings contain much sound literary criticism
as well as caustic comments on contemporary life. These
characteristics were already apparent in the first essay which
she contributed to the Atlantic Monthly (April 1886), entitled
" Children, Past and Present." In 1902 the university of
Pennsylvania conferred upon her the degree of Litt.D. She
was the author of Books and Men (1888); Essays in Miniature
(1892); Essays in Idleness (1893); Philadelphia the Place and
the People (1898); Compromises (1904); In our Convent Days
(1905); Americans and Others (1912); Counter-Currents (1915).
RESZKE, EOOUARD DE (1855-1917), operatic singer (see
23.201), died at Garnek, Poland, May 29 1917.
REVILLE, ALBERT (1826-1906), French Protestant theologian
(see 23.224), died in Paris Oct. 25 1906. His son, JEAN REVILLE
(b. 1854), died in 1908.
REYER, ERNEST (1823-1909), French musical composer
(see 23.225), died at Lavandou-sur-Huyeres Jan. 15 1909.
REYNOLDS, OSBORNE (1842-1912), British engineer, was
born at Belfast in 1842. He was educated at Dedham grammar
school and at Cambridge, and in 1868 became professor of
engineering at Owens College, Manchester, holding that post
for nearly 40 years. He was elected F.R.S. in 1877. He was
the author of over 70 papers on mechanics and physics published
in the transactions of learned societies, notably Sub-Mechanics
of the Universe, issued by the Royal Society, whose gold medal
hewonini888. (For his work .see 3. 581; 5.6458.783; 14.61; 22.806;
25.444; 28.428.) He died at Watchet, Som., Feb. 21 1912.
REYNOLDS, STEPHEN (1881-1919), English author, was born
at Devizes May 16 1881. Educated at Manchester University
and the Ecole des Mines at Paris, he became sub-editor of an
Anglo-French review in 1902 and the following year began an'
association with the Woolley brothers, fishermen of Sidmouth,
which lasted for some years. He thus familiarized himself with
fishing and the fisherman's point of view so far as to become a
recognised authority on the subject and a medium of communica-
tion between fishermen and the Government. He was a member
of the committee of inquiry into Devon and Cornwall Fisheries
(1912), and of the departmental committee on Inshore Fisheries
(1913), and in that year he was appointed adviser on Inshore
Fisheries to the Development Commission. In 1914 he became
also resident inspector of fisheries for the S.W. area. His
publications included A Poor Man's House (1908); Alongshore
(1910); The Lower Deck, the Navy and the Nation (1912); as well
as a novel, The Holy Mountain, (1909) and a volume of talcs.
He died at Sidmouth Feb. 14 1919.
RHODE ISLAND (see 23.248). The pop. of the state in 1920
was 604,397; in 1910, 542,610; an increase for the decade of
61,787, or 11-4 per cent. Rhode Island was still in 1920 the
most densely populated state, having 566-4 inhabitants to the
sq. m. (1910, 508-5)^ Every Federal census since 1790 has
shown an increase in density, and at a rate faster than that of
the United States as a whole.
The percentages of urban and rural pop. were in 1920: urban,
97'5%; rural, 2-5%; in 1910: urban, 96-7%; rural, 3-3%. The fol-
lowing are the cities of Rhode Island having a pop. of over 20,000
in 1920 and their percentage of increase in the decade 1910-20:
Providence .
Pawtucket .
Woonsocket
Newport
Cranston
Central Falls
East Providence
1920
1910
Increase
per cent
237.595
64,248
43.496
30.255
29,407
24,174
21.793
224,326
51,622
38,125
27.149
21,107
22,754
15,808
5-9
24-5
14-1
n-4
39-3
6-2
37-9
The proportion of native-born in 1915 (state enumeration) was
68-8%; of foreign-born, 31-2%. The foreign-born whites numbered
in 1920, 173,366, a decrease of 2-6% from 178,025 in 1910. During
the 10 years there has been a steady change in the proportions of
the various foreign elements in the population. Up to 1910 the largest
foreign-born element was Irish. In 1920 the Irish were numerically
inferior to the British and English-Canadian, the Italian, and the
French-Canadian. There has been a remarkable increase in the
number of Italian, Portuguese and Polish immigrants, and a notice-
able influx of Armenians and Syrians. " Foreign stock," i.e. foreign-
born and native-born of foreign parents, constituted, in 1915, 63-3%
of the whole population.
Agriculture. There has been a decline in farm acreage of 29-3%
in 30 years to 331, 600 ac. in 1920, and an even greater decline, Si' 2 %>
in improved acreage to 132,855 ac. in 1920. The number of farms
has fallen from 5,292 in 1910 to 4,083 in 1920. On the other hand
there has been a rise in both the aggregate and the average value of
farms, and in the value of crops (value of land and improvements,
1900, $26,989,189; 1920, $33,636,766; value of crops, 1909, $2,986,-
816; 1919, $5,340,378).
Fisheries. Fishing has, on the whole, declined in relative im-
portance. The shell-fish industry suffered severe loss, owing to the
pollution of the Providence river and the upper waters of Narragan-
sett Bay. From 1907 to 1920 the leased oyster grounds declined
from 21,000 to 7,000 ac. ; the state rentals, from $136,000 to $40,000;
and the output during the oyster season from 10,000 gal. daily to
2,ooogallons. In 1920 the Commissioners of Shell Fisheries reported:
" The Providence river has been practically destroyed as a suitable
place for the production or growth of shell-fish as food," the result
of contamination.
Manufactures. Rhode Island is preeminently a manufacturing
state. In 1914 it ranked igth among the states in the value of its
manufactures. The number of persons engaged in manufacturing
and mechanical pursuits nearly doubled in 20 years (1900, 101,162;
1910, 156,898; 1920, 196,205). The number of factories increased
from 1,678 in 1900 to 2,829 in 1919; the capital invested in manu-
RHODES RHODESIA
269
facturing from $183,784,587 in 1900 to $304,595,000 in 1914; and
the value of all manufactured products from $184,074,378 in 1900
to 8346,962,500 in 1916. Wages paid to factory employees in 1914
totalled $58,784,000; value added to products by manufacture, $116,-
030,000. Children under 16 years employed in factories numbered,
in 1920, 7,243, of whom nearly 5,000 were in textile mills. The effect
of the World War upon child labour in Rhode Island may be seen
from the following statistics: in 1915 children under 16 years con-
stituted 3-16% of all the factory operatives; in 1918, 4-44%; in
1919, 3-96%; in 1920, 3-69%. Textiles still held in 1920 the first
place among the manufactures of the state, employing 83,204 per-
sons. From 1910 to 1920, woollen and worsted mills increased in
number from 88 to 103 (with 463,342 spindles and 9,304 looms) ;
in employees, from 24,924 to 29,500; in value of products, from $74,-
600,000 to 890,000,000. Cotton mills increased in number from 106
to 130 (with 2,595,395 spindles) ; in employees, from 28,786 to
37,382; and in value of products, from $50,313,000 to $67,500,000.
Over 7,000 were persons employed in bleaching and finishing, 6,000
in the manufacture of silk and silk goods, and nearly 3,000 in the
manufacture of hosiery and knit goods. The combined value of the
products of these factories exceeded $20,000,000. Webbing and
braid were also produced in large quantities; and in recent years
tire fabrics have become an increasingly important article of
manufacture. Third among the industries of Rhode Island in 1920
were the machinery and metal trades, with 25,197 employees, and
products valued at $45,000,000. In the manufacture of jewelry and
silverware Rhode Island ranked first among the states. In 1914 the
value of the jewelry produced was more than one-fourth of the total
for the whole United States. The number of persons employed in
making jewelry, silversmithing, reducing and refining gold and silver
in 1920 was 14,052, in 322 establishments; and the value of the
product was estimated at 837,500,000.
Transportation. The railway mileage within the state in 1920 was
209-49 m -i electric and street railways, 351-5 miles. The construc-
tion of a branch of the Grand Trunk Railway system from Palmer,
Mass., to Providence was projected in 1910; but work was sus-
pended in Nov. 1912, and has not been resumed. Considerable sums
have been spent by the Federal Government for the deepening of the
channel of Narragansett Bay, for harbour improvement at Provi-
dence, Newport, Westerly and Pawtucket, ana for the construction
of harbours of refuge at Block I. and Pt. Judith. The foreign im-
ports of the customs district of Rhode Island amounted in 1920 to
$8,252,046. Foreign and domestic commerce passing through Narra-
gansett Bay in 1914 amounted to 8320,195,277.
Finance. The position of the state, Dec. 31 1920, was: assessed
valuation, $988,061,741 ; rateable wealth, $1,745,715,365 (about 82,-
890 per capita); receipts, $6,909,172; expenditures, $6,187,173;
bonded debt, 810,832,000; sinking fund, $1,631,917. June 30 1920
there were in Rhode Island three state banks, 17 national banks, 13
trust companies, 15 savings banks, and 10 other institutions for
savings and loans; with total resources of $416,339,951. From June
30 1918 to June 30 1920 the assets of the state banks increased 47 %;
of the trust companies, 21 %; of the savings banks, 20%; and of the
national banks, II %. Deposits in the savings banks, June 30 1920,
were 8113,200,366, an average of $630 per account. The average
savings deposit in 1918 ($582.95) was the largest in any state.
Charitable and Penal Institutions. In 1917 the Board of Control
and Supply and the Board of Charities and Corrections were super-
seded by a State Penal and Charitable Commission. The number of
the inmates in the institutions under the supervision of the Com-
mission was, in 1919, 3,241 (468 less than in 1918); and the amount
expended was $1,189,956. The budget for 1921 called for $1,562,394,
to which should be added about 821,000 in aid of various private
charitable organizations.
Education. The total school population (age 5 to 15) in 1920 was
123,705, of whom 106,142, or85>5 %, were in school. There were 83,-
525 in public schools; 20,690 in parochial schools; and 1,927 in
private schools. The total expenditure for education in 1920 was
$4,493,772, of which $999,850 was contributed by the state, the
remainder by the towns. In addition to its expenditure for primary
and secondary instruction and for normal training, the state annually
votes modest subsidies for the R.I. State College; the R.I. School
of Design; the R.I. College of Pharmacy; the R.I. Historical So-
ciety; the Newport Historical Society; and about 70 public libraries,