Clock reset. 



Aug. 12-13 ... " S.C."-" E." 237-1 sees, in 24 hours. 



13-H 237-1 



U-15 237-0 



15-16 237-2 



16-17 237-0 



17-18 236-9 



18-19 237-0 



The transit instrument was of a very old pattern by Troughton and Simms, and 

 was furnished with iron standards which could be screwed tight to a wooden box or 

 other pillar. The lens was of If -inch aperture and focal length about 23 Inches. The 

 lens should have been recemented before leaving England. A striding level of length 



o o o 



12 inches was provided, and was fitted with a new chambered level tube in London. 

 Unfortunately, the instrument reached the dock only a few hours before our departure, 

 and the level tube was then found to be already broken. Dr. Farr, however, very kindly 

 came to the rescue in Christchurch with the loan of another striding level ; but this 

 also was found to be cracked at one end on arrival at Winter Quarters. The end of 

 the tube was therefore cut off and plugged with a rubber cork. Later, the other end 

 of the tube also cracked and was also furnished with a rubber cork. Finally, the level 

 cracked down the centre and the fragments of glass were discarded. This, however, 

 did not occur until the end of the first year's observations at Cape Evans, so that the 

 level plugged with two corks was used during the whole of the first year. This suffered 

 from the defect that the spirit, in spite of our best efforts, slowly leaked out, and the 

 bubble became of unmanageable size after about five days' use. At the end of this 

 period it must therefore be dismantled for refilling. 



The diaphragm of the transit instrument was of glass ruled with 5 vertical wires 

 and 2 horizontal. The equatorial intervals between the wires were approximately 

 15 seconds each. All wires were observed with each star as there was not sufficient 

 time to reverse the instrument. 



The screws for the adjustment of collimation were very worn, as also those for 

 adjustment of focus, with the result that they could not be properly tightened. As 

 a consequence, it was early found that large changes in collimation were continually 

 occurring during the period of observation, so that the time results were discordant. 



The instrument was furnished with side axis illumination and with a small oil 

 lamp, but, as the wind was nearly always fairly strong during observations, the lamp 

 had continually to be relighted. It was therefore replaced by a small electric lamp 

 run from dry cells, packed with insulating seaweed in a large box. This box was brought 

 out from the warm hut at the start of the observations and taken back at the close. 



The most serious defect of the instrument was due to wear of the pivots, or possibly 

 to an actual " kink " in the axis. Thus, if the instrument was levelled when pointing 

 south, on transiting the telescope to point north, it was now considerably out of level. 

 At inclinations of the telescope to the horizontal, the level readings were different again 



32 



