OF THE SUN OBSERVED AT CAROLINE ISLAND, 1883. 
127 
13. If such assistance cannot be afforded, then, if the photoheliograph programme 
cannot be carried out in its entirety, the large pictures to be alone attempted. 
14. Special attention to the rating of the clocks, including the eclipse clock and 
siderostat, to be given at least three days before the eclipse. 
15. A quarter of an hour before totality, clocks to be wound, and caps and stops 
which had been hitherto used to diminish the amount of light to be removed, if 
necessary. 
16. The timekeeper should be asked to give these instructions in a loud voice, as 
experience has shown that this is apt to be forgotten. 
17. In the observations and adjustments during the eclipse, no deviation from the 
time table and adjustments to be made except after consultation, and with the 
approval of the American astronomer in charge. 
18. The clockwork of the integrating spectroscope to be so adjusted that the plate 
will fall through one inch in eight minutes. 
19. The distance of plate from concave grating to be that given by Captain Abney 
for vertical distortion. 
20 . In equatorial, the slits to be parallel and vertical in the meridian, and their 
centres lying on the same part of the sun. 
21. All slits to be in. = No. 2 on Captain Abney’s screw, with the exception of 
the integrating spectroscope, which should be - 3^0 in. 
22 . At some convenient time—say 100 secs.—near the middle of totality, the slits 
of equatorial to be brought to the point of reappearance. 
23. The plates to be developed and copied at the first convenient time after the 
eclipse is over. 
24. Half the positives and half the negatives to be handed to the British Consul at 
Callao, to be forwarded to the Foreign Office for transmission to the Science and Art 
Department by the next mail after that by which the observers leave. 
25. On arrival at Callao, a cypher telegram to be despatched to Secretary, Ken¬ 
sington Museum, London, giving the results obtained with each instrument, and 
stating any other matter of importance. 
26. Great care to be taken in repacking the instruments after the eclipse. Tin 
cases to be re-closed. 
27 . A detailed report, to be prepared before arrival at Callao, of the general results 
to be posted to me immediately on arrival at Callao, in case of any delay en route. 
28. If a convenient opportunity arises for sending this report from the Marquesas, 
this course to be followed as well as the other. 
29. It is to be understood that the records of the eclipse are the property of the 
British Government. 
30. In case no pictures are taken with the small photoheliograph, Mr. Lawrance 
IS requested to ask the American astronomer in charge for an oriented positive of the 
corona to facilitate reference here. 
