1915] on the Total Solar Eclipse of 1914 359 



a suitable site for our instruments at Hernosand, and obtained the 

 expediting of our cases by the Custom-house officials after a merely 

 formal inspection. At Hernosand the Rector of the Technical 

 School, Herr Tham, placed his school, containing physical and 

 chemical laboratories, mechanics, and carpenters' shops, and a dark- 

 room, entirely at our disposal, and that of an expedition from 

 St. Ignatius' College, Valkenburg, Holland, consisting of Father 

 AVulf and Father Rodes. The Technical School had an efficient 

 electrical installation, and Herr Helenius, the town electrician, laid 

 down leads gratuitously, so that we were enabled to employ the 

 current at our instruments. We finally chose to erect these in a 

 field at the back of the Technical School, at an altitude of about 

 300 feet above sea-level. The co-ordinates of the station were : 

 latitude 62' 38' 8 '8" X., and longitude 17° 57' 32*25 E. of 

 Greenwich. The computed duration of totality was 129 seconds. It 

 really was 125 seconds. The station was 3*9 miles from the 

 central line of totality. 



Our experiences in the erecting and adjusting of the instruments 

 are described in some detail in the Preliminary Report of the expedition, 

 communicated to the Royal Astronomical Society by the Joint Per- 

 manent Committee.* It will be only necessary, therefore, to summarize 

 some of the more important details. The members of the expedition, 

 in addition to myself, were Father O'Connor, of the Stonyhurst College 

 Observatory ; Mr. G. J. Gibbs, of Preston ; and Mr. E. T. Whitelow, of 

 Birkdale, Southport. Our instrumental equipment included a 16-inch 

 coelostat belonging to the Royal Astronomical Society, and an 8-inch 

 " Grubb " coelostat, kindly lent by the Royal Irish Academy. The 

 16-inch coelostat supplied light to three coronagraphs and a horizontal 

 telescope for projecting an enlarged image of the sun on to a circu- 

 larly graduated screen of ground glass. The long focus coronagraph 

 had an O.G. of 4 inches aperture, and focal length 20 feet. This also 

 was kindly lent by the Royal Irish Academy. The image of the sun 

 for best focus was 2^ inches in diameter. For obtaining images of 

 the filmy extensions of the coronal streamers we employed two cameras, 

 one with a 4-inch O.G., focal length 34 inches, the other with O.G. 

 3"5 inches and focal length 12 inches. Our programme of exposures 

 included six exposures with the long-focus lens of 2, 4, 10, 25, 7, 3 

 seconds respectively. All these, except the first, were successfully 

 made by Father O'Connor. With the 34-inch coronagraph four 

 exposures of 10, 50, 15, 5 seconds were secured, and with the 12-inch 

 camera one long exposure of 95 seconds. These two instruments were 

 under the charge of Mr. Whitelow. The plates employed were bathed 

 by Mr. Crowther, of Carlisle, in a solution to render them impervious 

 to solarization. In addition to these two cameras Mr. Whitelow had 

 mounted on a wedge-head, cut to the latitude of Hernosand, a Zeiss lens 



* Monthly Notices, RA.S. Ixxv. No. 3, January, 1915. 



