The third station at Wardha, on the Great Indian Peninsula Railway from Bombay to Nagpur, will be occupied by Mr Newall, who proposes to use a large spilt spectroscope, with two prisms of 62 degrees, in the attempt to determine the speed of rotation of the corona by the relative displacements of its lines as observed east and west of the Sun.
In the same neighbourhood, Captain Hills will probably fix his apparatus, which will consist of two slit spectroscopes, having the slit tangential to the Sun’s limb at the point of second contact and diametral receptively. The slits are 1.5 x 0.004 inches and 2 x 0.004 inches respectively; and the prisms are, for the first spectroscope, of two flint prisms of 60 degrees, 4.5 inch base, 2.5 inch height at maximum deviation for Hydrogen gamma and for the second spectroscope, of four quartz prisms of 60 degrees, 3.25 inch base, 2.75 inch height at maximum deviation for Hydrogen epsilon. The collimator and camera lenses are single quartz lenses, of 2.5 inch aperture , 30 inch focus and 3 inch aperture and 36 inch focus.
The objectives are all achromatic Cooke lenses of 4.5 inch aperture, 5 feet 10 inches focus, and a single quartz lens of 5 inch aperture, 4 feet 9 inches focus
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