(591) 
Juurus and NisLanp, the objective grating spectrograph to be erected 
near the northern limit of totality. 
Messrs. MULLER, WILTERDINK and NigLanp had in the meantime 
drawn up a programme for the astronomical observations while Mr. 
Jurrus did the same for the physical observations, so that on the 9th 
of May the practice drills with the officers and men of the Sumatra 
could begin. 
The work was divided as follows: 
Chronometers and Siderostats: 5 assistants ; 
Large spectrograph: Mr. S. Frioer with 2 assistants ; 
Small spectrograph: Mr. pr RocneMoNT with 6 assistants ; 
Spectroscope: Mr. Husrecut with 3 assistants ; 
Prismatic camera: Mr. NwLanpd with 4 assistants ; 
„40-feet” coronagraph: Mr. MULLER with 3 assistants; 
10-inch” coronagraph: Mr. Wackers with 5 assistants ; 
Coronagraphs on polar axis: midshipman BRANDT with 10 assistants ; 
Photometer: Mr. VAN BEMMELEN and midshipman Baron Mackay 
with 2 assistants ; 
Actinometer : Mr. Jurrius with 4 assistants ; 
Polarimeter: lieutenant v. D. Escn with 3 assistants ; 
Pyrheliometer: 2 assistants ; 
Cloud-theodolite: lieutenant DE Bruyne with I assistant; 
Observations of wind: 2 assistants ; 
Thermometers: 4 assistants ; 
Atmospheric electricity: Mr. Tu. Ficarn; 
Declinometer: 2 assistants ; 
Drawings of corona: midshipman BALsEM with 4 assistants; 
Shadowbands and further observations: midshipmen LANGELAAN 
and Buppine with 14 assistants ; 
Look-out: one assistant ; 
The total number of observers was thus 93, of whom 7 were 
officers and 68 non-commissioned officers and men of the Sumatra. 
The uncertainty of the longitude of the place of observation and 
the experiences from former eclipses pointed to the desirability of 
deriving the last warning sign of ,ready” not from the computation, 
but from the observations of the eclipse itself. It was arranged that Mr. 
Mutter should give this sign, when in the dark hut of the 40-feet corona- 
graph the crescent of the sun measured 45°. According to computation 
this would occur 168 before the beginning of totality. Moreover, the 
look-out was to watch the search-light of the English man-of-war 
Pigmy, stationed at Aoer Gadang, which light would, at our request, 
be screened off at the moment when totality began at that station, 
