342 
CAPTAIN L. DARWIN, DR. A. SCHUSTER, AND MR. E. W. MAUNDER 
IX. Photographic Results obtained at Carriacou Island. 
By E. W. Maunder. 
The work allotted me in the observation of the eclipse Avas purely photographic, 
and was intended to be, in its general character, a duplication of that undertaken by 
Dr. Schuster. The photographs vehich I was to take were to be both of the corona 
itself and of its spectrum. Por the former I was provided with a lens of about 
inches aperture, corrected for the photographic rays, and having a focal length of 
about 5 feet. The diameter of the image of the Moon on the photographs, which 
were taken in the primary focus, was therefore about six-tenths of an inch. For the 
photographs of the spectrum I had two spectroscopes, the second of which was only 
provided immediately before the instruments were packed up for shipment. The first 
spectroscope had two prisms, each 175 inch in height and 2’5 inches in base, and with 
refracting angle of 62° ; and it was used in conjunction with a condensing lens of 
o'5 inches aperture, and focal length of 17'5 inches. The second spectroscope had 
one prism, 2‘6 inches both in height and base, and v.dth refracting angle of 60°; the 
condensing lens used to throw an image of the Sun on the slit of this spectroscope 
was 3 inches in aperture, and had a focal length of 14‘5 inches. These three instru ¬ 
ments Avere all attached to the same frame, which was mounted equatorially and 
supplied Avith clock-work. The polar and declination axes and the R. A. and 
declination circles were those of the Corbett Equatorial of tlie Royal Observatory, 
Greenwich; the driving-clock also belonged to the same instrument, but the stand to 
which these Avore attached was made specially for the expedition. It Avas a tripod 
stand, composed of pieces of angle iron bolted together, and Avas found to be light and 
portable, and at the same time strong and steady. In addition to the camera and 
spectroscopes, a telescope of 3'6 inches aperture and 5 feet focal length, together with 
its finder, was mounted on the same stand ; and a lens of 1 inch aperture and 4 feet 
focal length, Avith a little screen in its primaiy focus, was attached to the side of the 
coronal camera as a finder. 
Owing to a delay in the selection of tlie equatorial mounting to be assigned to my 
use, aiid to the fact that the second spectroscope Avas added to the equipment as an 
afterthought, the preparation of the entire instrument was thrown so late that it was 
completed only just in time to be packed for shipment, and I had no opportunity, 
even for a moment, to test its performance as a Avhole, or of the diiferent parts sepa¬ 
rately, except the coronal camera, until my arrival at Carriacou. On setting iip the 
instrument there, it Avas at once seen that the dtiAuno’-clock droA^e in the wrong 
direction, the Corbett equatorial liaving been last used in the Southern hemisphere. 
By the help of one of the artificers of the “ Bullfrog” this Avas altered, and the driAung 
of the clock rendered fairly good. Its actual rate aatis not determined, as the neces¬ 
sary alterations were not conjj)leted until tlie day before the eclipse. But the gearing 
