24 



Observations of Fenian/ 1 to G, 1903. 



Observations were taken under exactly similar conditions to those taken in July and August, 1902. The 

 pressure was about the same and the temperature fairly uniform throughout. The method of noting 

 coincidences and the distance of the flash apparatus from the pendulums were the same as previously. 

 The flash apparatus worked well. When completing the last pendulum swing the vacuum suddenly failed. 



On taking the case off, small risings were found in the rims of the base near the supporting screws. The 

 rim had to be re-surfaced, which process delayed the completion of the observations until February 6. 



Observations of September 5 and 6, 1903. 



The pendulum apparatus was set up in a similar manner and in exactly the same spot as in July- 

 August, 1902, and February, 1903. The distance between the pendulums and scale was a little greater 

 than before, viz., 2932 millims. Preparations were made to commence observing on the 4th. Observing 

 was commenced at about 10 a.m., with everything in good adjustment and the temperature of the chamber 

 + 1 C., but, unfortunately, soon after starting, the mirrors and prisms under the receiver became " fogged " 

 and covered with moisture, and observing had to be discontinued. 



The thorough drying of the pendulum apparatus and readjustments occupied the rest of the day, and 

 observing had to be postponed until the 5th. 



An unsuccessful attempt was made during the evening of the 4th to take transit observations of stars 

 for determining the rate of the chronometer. The portable instrument supplied to the Expedition was not 

 of a very satisfactory character, the axis or pivots which rest in the V's being so worn that the telescope 

 would not remain at any required altitude. The low temperature nearly - 40 F. so contracted the 

 spirit in the striding level that the ends of the bubble could not be seen, and therefore no value for level 

 error could be determined. The cold was also extremely trying to the observer, who was compelled to 

 give up the attempt after about two hours. The subsequent nights were overcast. The rate of the 

 chronometer was therefore determined, as on the previous occasions, by comparison with the "Discovery's" 

 chronometers. 



Complete sets of swings were taken on the two following days, September 5 and 6, Engineer Commander 

 SKELTON rendering assistance throughout and observing independently. 



LOCAL GEOLOGY. 



The Winter Quarters were situated near the end of a peninsula running out in a south-westerly direction 

 from the base of the island formed by Mounts Erebus and Terror. The peninsula is about ten miles long 

 by a mile broad, and has an average height of 600 to 700 feet. The rocks of which it is composed are of 

 practically three varieties : 



1. A yellow breccia, which occurs in three well-marked heights, the nearest of which is three miles 

 distant from Winter Quarters and 1400 feet high. This rock does not appear to be developed to any 

 great extent, but occurs as a volcanic pipe surrounded by the basalt which forms the major part of the 

 peninsula. 



2. The trachyte found on Observation Hill, a hill three-quarters of a mile distant from the ship and 

 750 feet in height. This hill is conical in shape, the upper half being composed of a trachyte of specific 

 gravity 2 2, and the lower half of a lava containing Japilli of a very varying composition and with a 

 specific gravity of 2 -87 in one case, but on the south-cast side of it there is a rock of greater specific 

 gravity. 



3. A black basalt, which is by far the most important rock both as regards its development and physical 

 properties. It forms the hill called Harbour Height and reaches from Hut Point to the base of Castle 

 Rock, if not beyond it. It forms three-quarters of the rock of the peninsula, and rises to an average 

 height of 700 feet between the two points mentioned above and lies roughly perpendicular to the magnetic 

 meridian. It has a specific gravity of 2 9, and under the microscope shows frequent plates of magnetite. 

 Hut Point is entirely formed of it, and it is on this rock that the pendulum observations were made. 



