304 THE LATER JOURNEY
home safely but of course without results [N2]. Frustration continued also after
November 18, 1915, the day on which Einstein announced the right bending of
1''74 [E30]. Ten days later, commenting on a new idea by Freundlich for mea-
suring light bending, Einstein wrote to Sommerfeld, 'Only the intrigues of mis-
erable people prevent the execution of this last, new, important test of the theory,'
and, most uncharacteristically, signed his letter 'Your infuriated Einstein,' [E31].
An opportunity to observe an eclipse in Venezuela in 1916 had to be passed up
because of the war. Early attempts to seek deflection in photographs taken during
past eclipses led nowhere. An American effort to measure the effect during the
eclipse of June 1918 never gave conclusive results.* It was not until May 1919
that two British expeditions obtained the first useful photographs and not until
November 1919 that their results were formally announced.
English interest in the bending of light developed soon after copies of Einstein's
general relativity papers were sent from Holland by de Sitter to Arthur Stanley
Eddington at Cambridge (presumably these were the first papers on the theory to
reach England). In addition, de Sitter's beautiful essay on the subject, published
in June 1916 in the Observatory [S2], as well as his three important papers in the
Monthly Notices [S3] further helped to spread the word. So did a subsequent
report by Eddington [E33], who in a communication to the Royal Astronomical
Society in February 1917 stressed the importance of the deflection of light [E34].
In March 1917 the Astronomer Royal, Sir Frank Watson Dyson, drew attention
to the excellence of the star configuration on May 29, 1919, (another eclipse date)
for measuring the alleged deflection, adding that 'Mr Hinks has kindly under-
taken to obtain for the Society information of the stations which may be occupied'
[Dl]. Two expeditions were mounted, one to Sobral in Brazil, led by Andrew
Crommelin from the Greenwich Observatory, and one to Principe Island off the
coast of Spanish Guinea, led by Eddington. Before departing, Eddington wrote,
'The present eclipse expeditions may for the first time demonstrate the weight of
light [i.e., the Newton value]; or they may confirm Einstein's weird theory of non-
Euclidean space; or they may lead to a result of yet more far-reaching conse-
quences—no deflection' [E35]. Under the heading 'Stop Press News,' the June
issue of the Observatory contains the text of two telegrams, one from Sobral:
'Eclipse splendid. Crommelin,' and one from Principe: 'Through cloud. Hopeful.
Eddington' [01]. The expeditions returned. Data analysis began.* According to
a preliminary report by Eddington to the meeting of the British Association held
in Bournemouth on September 9-13, the bending of light lay between 087 and
double that value. Word reached Lorentz.f Lorentz cabled Einstein, whose excite-
*For many details about all these early efforts, see especially [E32].
**I shall not discuss any details of the actual observations or of the initial analysis of the data and
their re-analysis in later years. For these subjects, I refer to several excellent articles [Bl, E32, Ml].
•(•The news was brought to Leiden by van der Pol, who had attended the Bournemouth meeting [L3].