Proceedings of Societies. 201 
of different qualities was made sensitive in London, and some was taken 
not rendered sensitive, so as to secure as far as possible good results. 
Distilled water, weighing 139 1b., had to be included; and engineers’ and 
carpenters’ tools, weighing 113 lb., were taken. Mr Cassella lent some 
thermometers and a barometer, and Messrs Elliott an aneroid barometer, 
to the expedition. 
The preparations were commenced by Mr Beckley (of the Kew Obser- 
vatory) early in the year 1860; and in June Mr De La Rue engaged Mr 
Reynolds to assist Mr Beckley in completing them. Mr Beckley and Mr 
Reynolds were charged with the erection of the observatory at Rivabel- 
losa ; and so well were the plans organised, that the observatory and helio- 
graph were in actual operation on the 12th of July, the expedition having 
sailed from Plymouth in the Himalaya on the morning of the 7th. 
This could not, however, have been so expeditiously accomplished without 
the energetic co-operation of Mr Vignoles, who met the Himalaya in 
a small steamer he had chartered to convey the expedition and their ap- 
paratus into the port of Bilboa, and who despatched the Kew apparatus 
as soon as it was landed to the locality he and Mr De La Rue had agreed 
upon. This was situated seventy miles distant from the port of landing, 
and accessible only through a difficult pass. Mr Vignoles had also taken 
the trouble to make arrangements for accommodating the Kew party, and 
for the due supply of provisions—a matter of some importance in such a 
locality. . 
ee Mr De La Rue, Mr Beckley, and Mr Reynolds, the party con- 
sisted of Mr Downes and Mr E. Beck, two gentlemen who gave their gra- 
tuitous services, and of Mr Clark, who acted as interpreter, and who also 
kindly assisted during the eclipse. Hach of the party had only one thing to 
attend to, and thus rapidity of operation and certainty of result were 
secured. ‘The total expenditure of this expedition amounted to L.512; 
the balance of’ 4.362 over the amount granted by the Royal Society has 
been generously defrayed by Mr De La Rue. 
Upwards of forty photographs were taken during the eclipse, and a 
little before and after it, two being taken. during the totality, on 
which are depicted the luminous prominences with a precision impos- 
sible of attainment by hand drawings. The measurements which have 
been made of these prominences by Mr De La Rue show incontrovertibly 
that they must belong to the sun, and that they are not produced by the 
deflection of the sun’s light through the valleys of the moon. The same 
prominences, except those covered over during the moon’s progress, cor- 
respond exactly when one negative is laid over the other ; and by copying 
these by means of a camera, when so placed, a representation is obtained 
of the whole of the prominences visible during the eclipse in their true 
relative position. The photographs of the several phases of the eclipse 
have served to trace out the path of the moon’s centre in reference to the 
sun’s centre during the progress of the phenomenon. Now, Rivabellosa 
being north of th2 central line of the moon’s shadow, the moon’s centre 
did not pass exactly across the sun’s centre, but was depressed a little 
below it, so that a little more of the prominences situated on the north 
(the upper) limb of the sun became visible than would have'’been the case 
exactly under the central line, while, on the other hand, a little of those 
on the southern limb was shut off. It has been proved, by measuring the 
photographs, that the moon during the totality covered and uncovered the 
prominences to the extent of about 94” of arcin the direction of her path, 
and that a prominence situated at aright angle to the path shifted its 
angular position with respect to the moon’s centre by lagging behind 5° 
55’. On both the photographs is recorded a prominence, not visible opti- 
cally, showing that photography can render visible phenomena which 
