TOTAL ECLIPSE OF THE SUIT APRIL 16, 1893. 
559 
The Instrument Employed. 
The 6-inch prismatic camera employed in Africa has a focal length of 7 feet 6 inches, 
and the spectrum obtained is about 2 inches long from F to K. Rings corresponding 
to the inner corona are about seven-eighths of an inch in diameter. 
The object glass and prism, with the square tube to which they were attached, were 
kindly lent for the occasion by the Department of Science and Art, and the equatorial 
mounting was that of Professor Lockyer’s 6-inch Cooke refractor. The tube is a 
strong mahogany one, square in section, and it was attached to the declination axis 
by means of a suitable iron plate. In order to reduce the weight of the instrumental 
equipment, the heavy iron pillar of the equatorial was replaced by a rough wooden 
stand which was filled up with concrete after being placed in position. Provision was 
made for the clock bracket and fine adjustments of the polar axis, and the whole 
arrangement was quite satisfactory. 
Fig. 1. 
Prismatic Camera mounted on equatorial stand. 
Fig. 1 represents the instrument as adjusted for use in latitude 14° 3' N. When 
actually in use, the camera was steadied by a stiff* wooden rod screwed to the end of 
the tube, and bearing on the end of the declination axis ; this did not interfere with 
the driving gear and materially contributed to the successful results, as on account 
of the great weight of the prism it was necessary to bring a large part ot the tube 
