354 
REV. S. J. PERRY ON THE TOTAL 
1. The Jpnes 4-inch equatorial, provided with a Hilger solar prism and power of 
110, was destined for observations of first and last contacts; but, as it was raining 
heavily both at the beginning and at the end of the eclipse, this notice of the prepara¬ 
tion for contact observations will amply suffice. 
2. After contact, the solar prism was to be dismounted, and a large direct-vision 
spectroscope by Browning substituted in its place, to be used during totality as an 
analysing instrument by Lieutenant Pascoe, R.N., assisted by Dr. Archer. 
3. Dr. Wright, R.N., had charge of the Hilger direct-vision spectroscope, mounted 
on its own stand, and to be used as an integratiim instrument. The observations 
with this spectroscope, and also those undertaken by Lieutenant Pascoe, were 
intended to supplement any results obtained with the grating attached to the 
5^-inch Alvan Clark equatorial. 
4. Mr. Maunder’s work with the photoheliograph and spectroscopic cameras, 
which will form the subject of a separate report. 
5. Drawings of the streamers of the outer corona, to be made with the aid of disks 
obscuring the inner corona. The sketches of Captain Masterman, R.IST., and of 
Paymaster Osburn, R.N., will be appended to this report, with their own remarks 
explanatory of the nature of the results obtained. 
6. Spectroscopic observations with a Howland grating attached to the 5-g-inch 
Alvan Clark equatorial. The telescope to be pointed by Lieutenant Helby, and 
the readings taken by Father Perry. 
This equatorial of Alvan Clark was the instrument used by the Bev. T. Webb in 
the preparation of his well-known wmrk on “ Celestial Objects.” The glass was one 
of those guaranteed by Mr. Dawes, and it would be difficult to surpass it in excellence 
of defining power. The mounting was not comparable with the quality of the glass, 
and no driving clock was attached. Mr. Webb used only a slow motion in B.A.; but, 
as it was necessary to vary the position of the slit of the spectroscope during totality, 
in order to place it successively on different parts of the corona, it became imperative 
to provide a slow motion for N.P.D. before taking the instrument to the West Indies. 
This addition was made by Cooke, of York, and he also arranged the clamps so that 
the telescope might be fixed firmly in every direction. The absence of clockwork to 
drive the instrument made it necessary to have an assistant to point the telescope, and 
therefore Lieutenant Helby, of H.M.S. “ Sparrowhawk,” was chosen for this work. 
The grating used with this equatorial was kindly lent by the authorities of South 
Kensington; but a direct-vision spectroscope, constructed by Hilger, was also 
provided, by which an equal dispersion could be obtained, and which might replace 
the grating in case of accident. The plate of the grating was polished and figured by 
J. A. Brashear, and the parallel lines, 14,438 to the inch, were ruled on Professor 
Rowland’s engine at Baltimore in 1884. The plate was mounted b}^ Hilger on a 
student’s spectrometer belonging to Stonyhurst. The combination answered very 
well, and gave little trouble in the adjustments. 
