76 J. Wafcerhouse — Photography in connection with [No. 2, 



Glacial Acetic acid 40 cub. cents. 



Spirits of Wine 30 „ „ 



Water r 1000 „ „ 



A solution of cyanide of potassium was used for fixing. 



It was considered advisable not to intensify the plates, but to obtain 

 the greatest possible intensity from the first development. 



As the plates were developed they were placed in a draining rack in 

 order as taken and put aside till after the Transit. 



The distribution of duties was arranged as follows : — 



I remained at the Photoheliograph to expose the plates at every two 

 minutes and record the times of exposing each plate by the clock dial, 

 which had previously been ascertained to agree with the standard clock, 

 carefully noting any variation in the intervals and any other noteworthy 

 circumstance connected with any of the plates. At every sixth plate, with 

 a few exceptions, the cross-wires were replaced by the reticule. 



Sergt. Harrold developed the plates and generally supervised the 

 operations in the dark-room. He was directed to take special care that the 

 plates were arranged in the racks in their proper order of sequence as deve- 

 loped, and to note in writing any variations. He was at once to inform 

 me of any defects in exposure or in the position of the image on the plate. 



Corporal George coated the plates with collodion and sensitised them. 

 He was responsible that the plates were taken in the proper order, as num- 

 bered and arranged in the boxes, and was ordered to at once report any 

 change. In case of having to pass over any of the marked and numbered 

 plates, he was to properly number the plates substituted for them. In 

 order that the position of the sun's image might be the same on all the 

 plates, he was ordered when coating the plates with collodion to keep the 

 unnumbered side of the plate uppermost, with the numbered corner away 

 from him on his right hand, pouring off the collodion at the near right- 

 hand corner. 



Private Fox took the plates out of the baths and placed them in the 

 slide so that the numbers might be at the upper left-hand corner of the 

 slides and the thick collodion at the lower left-hand corner. (This arrange- 

 ment of the plates when being coated and placed in the slides was observed 

 throughout all drills and practice plates, and answered the purpose perfect- 

 ly.) He then placed the dark slides in the receptacle in the door from which 

 they were passed into the dome by the man in the passage between the 

 doors. It was also his duty to carry the Janssen slide into the dome, place 

 on and take off the No. 1 counterpoise, which was fixed at the end of the 

 declination axis, and carry the Janssen plates back again for development. 

 In case of there being any delay in a wet plate being ready at the proper 

 time, he was to keep a dry plate in readiness to be sent in instead, notify- 



