Page:Proceedings of the Royal Society of London Vol 69.djvu/254

238 the central line, 6 miles distant from the camp of the Dutch observers at Karang Sago, and 30 miles from Padang.

Erection of the Huts and Instruments. The same light wooden frames covered with Willesden waterproof canvas which were used at Ovar in the eclipse of 1900, May 28, were taken out to Sumatra, with an additional one to serve as a developing room.* As a protection against sun and rain, these were supplemented by sheds, built in Malay style, of bamboos and thatched with atap, a species of palm leaf, which is obtained tied on laths about 4 feet long.

One open shed, 14 feet long and 12 feet broad, and 12 feet high at the gable, covered one of the two canvas huts and half of the second one, in which the Thompson coronagraph and the 16-inch coelostat were placed. As at Ovar, the hut over the coelostat was moved back a few feet during observations. Thatch was tacked on the roof of this hut. Similar sheds were fixed over the spectroscope hut and over the developing room. Thatch was also tacked all over the developing room hut. This, in addition to black waterproof paper inside, served to make the room light-tight. Movable sheds, each resting on four stout bamboos, were placed over the heliostat and condensing lenses of the spectroscopes and over the Dallmeyer photoheliograph. A house of bamboo and atap was also built, open on the east side and partly on the north, in which hammocks were swung, and where the observers lived at times when the " Pigmy " was obliged to leave for a short time. A tent was also erected for the two marines who were left on shore with the observers by Lieut, and Com. Oldham on such occasions. The general arrangement of the station is shown in the accompanying diagram. These huts, which were very satisfactory, were built under the superintendence of two Malay employes of Mr. Delprat, the Director of Railways.

The coelostat was mounted on a concrete pier sunk about 18 inches into the ground, and rising 4 inches above it. The clock was screwed on to a box which was partly let into the ground, the weight being carried over a pulley on an iron bracket fixed on a palm-tree at a height of about 12 feet. The Thompson tube was mounted on boxes The table of the spectroscope was placed on four brick piers 4 feet high. The heliostat and condensing lenses were placed on a heavy box which rested on two rows of bricks, which raised it about 4 inches above the ground, the bricks being fixed on a bed of concrete. A foundation of brick and concrete was also provided for the Dallmeyer photoheliograph. In the building of the foundations, erection of piers, and putting together of the canvas huts we received every assistance from the officers and men of the "Pigmy," and are specially indebted to Lieut. Briggs and the engineer, Mr. Townsend. The erection of the huts and instruments occupied us till the beginning of May.


 * ' Roy. Soc. Proc.,' vol. 67, p. 393.