188 



SCIENCE 



[Vol. VI., No. 135. 



tory peak, and stored for use at the houses and 

 stables just below. 



As Mr. Lick gave specific direction that the 

 income from his endowment of the observatory 

 should be made ' useful in promoting science,' 

 his trustees wisely made thorough provision for 

 observing the transit of Venus of 1882. A 

 photoheliograph, for obtaining very accurate 

 pictures of the sun, was added to the perma- 

 nent equipment of the observatory, for the 



purpose of co- 

 operating with 

 the Ameri- 

 can transit- 



clear with exceptionally fine conditions of 

 vision. The solar eclipse of the 16th March, 

 1885, was also photographed at the observa- 

 tory, under very favorable atmospheric con- 

 ditions. 



The illustration of the ground-plan of Ob- 

 servatory peak shows the exact location of all 

 the buildings on the main plateau, and the ar- 

 rangements of the rooms of the principal edifice. 

 This is mostly a single story high ; and like all 

 the other buildings containing instruments, 

 and the dwelling-house also, is fire-proof in 

 construction. The interior finish of the main 

 building is of superior quality throughout : the 

 hall, about two hundred feet in length, with its 

 floor and wainscot of marble, affords an excel- 

 lent space for optical experiments. The dia- 

 gram shows also the position at the ex- 

 treme south end of the plateau, which 

 will ultimately be occupied by 

 the great telescope. 



Among the principal 

 instruments of the ob- 

 servatory is the Rep- 

 sold meridian- 

 circle. Its ob- 

 ject-glasses 

 are six-and- 

 one-third 

 inches 



Fig. 2. — Lick observatorv. Ground plan and summit plateau. 



of- Venus commission. The president of the 

 trustees invited Professor Todd to direct the 

 observations on Mount Hamilton ; and the ex- 

 cellence of the photographs obtained b}^ the 

 expedition is largely due to the wide experi- 

 ence of his photographer-in-chief, Mr. Lovell of 

 Amherst. The work of the expedition has been 

 fully described in Science, vol. i. p. 94 ; and the 

 j-esults obtained from these photographs have 

 been incorporated with those secured under the 

 immediate direction of the American commis- 

 sion. The period of residence of the party on 

 the mountain (Nov. 21 to Dec. 21) included 

 four nights totall}^ cloud}', fourteen parti}' 

 cloud}', six clear with good seeing, and seven 



in diameter, and were made by the Clarks. A 

 house of unusual construction and proportions 

 (at the left of the square tower in the centre of 

 the ' near view,' fig. 3) has been built to shelter 

 this instrument. The building is forty-three 

 feet by forty-five, with an offlce-wing adjoin- 

 ing. It has double walls, the interior of wood, 

 and the exterior of iron, with abundant space 

 between for ready access to any part ; and the 

 arrangements for securing the same tempera- 

 ture within as without are perfect. The shut- 

 ters closing the observing-slit are of a novel 

 pattern, the device of Mr. Eraser. The interior 

 of the observing-room is of California red-wood 

 with a high finish. At the right, in the illustra- 



