INTENSITY OF CORONAL LIGHT DURING THE SOLAR ECLIPSE OF 1886. 371 
all available occasions in their duties. The driving clock of the equatorial gave 
trouble in the outset, but it was eventually got into order, and on the day of the 
eclipse, and for some days previously, ran sufficiently well. The constant dampness 
of the ground, and consequent absence of dust, probably contributed to its good 
behaviour. 
The duration of the total phase of the eclipse at Hog Island was about 230 seconds. 
We found that a simple and sufficiently accurate method of informing the party as to 
how this time was speeding, and of the amount of time still left at intervals of 
I 5 seconds before the end of totality, could be obtained by observations made with a 
14-second sand-glass, such as is employed on shipboard in heaving the log. 
The arrangement of the party was as follows :— 
Integrating box .... Lieutenant Angus Douglas. 
Galvanometer.Mr, Webb, 
Bar photometer .... Lieutenant Baibnsfather. 
Recorder.Mr. Robert J ackson. 
'These instruments were placed close together in a small marquee. Each observer 
had in addition a man to charge and connect up a battery of Grove cells for the glow 
lamps. 
Equatorial photometer , . Professor T. E. Thorpe. 
Galvanometer.Mr. H, A. Lawrance. 
Disc observations .... Captain Archer. 
On the day before the eclipse the following instructions were issued to the observers 
in charge of the integrating apparatus :— 
Instructions to Lieutenant Douglas. [Integratiny Box.) 
1. The eclipse begins at 6hr. 12m. L.M.T. Totality commences at 7hr. 10m., and 
lasts about 230 seconds. 
2. It is desirable that on the morning of the eclipse you should be ashore not later 
than 6 a.m. (It is assumed that your integrating box, leads to galvanometer, glow 
lamp, and resistance apparatus are left in position over night.) Ascertain that 
the box is in proper azimuth, and test by the Abney level that the inclination is 
about 19°. 
3. See that the connections to the glow lamp are properly made, and that the 
galvanometer is levelled on the cement foundation and is in ad-jiistment. 
4. Give instructions to have a battery of 7 cells in readiness for you, jiot later tlian 
6.30: 6 cells to be connected up, the seventh to be reserved in case of accidents. See 
that you have actually 6 cells connected up before you begin. 
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