70 Transactions. — Miscellaneous. 



south polar circle not a single determination has been con- 

 sulted, because there are none." The accordance of gravity 

 determinations obtained in the two hemispheres alluded to 

 above has reference to the third column of the table, in which 

 the length of the seconds-pendulum for each place, obtained by 

 experiment, is used to calculate what should be the length of 

 a seconds-pendulum in lat. 45° on the assumption that the 

 earth is an ellipsoid of which the equatorial radius is 3962-802 

 miles and the polar radius is 3949-555 miles, and that the 

 centre of gravity is at the centre of form. The values so 

 obtained do not differ widely, and give a mean of 0-993577 

 metres — not far different from the computed length for 45°, nor 

 from the ascertained length at Kerguelen, lat. 49° 8' 9". But 

 it will be observed that there is a very notable difference in 

 the values of G. at about the same latitudes in the two hemi- 

 spheres, the force of gravity being greater in the Northern than 

 in the Southern Hemisphere. 



A comparison of the values in the two Shetlands, North 

 and South, however, is the last that is at present available 

 towards the poles, and it therefore appears of great scientific 

 interest that further pendulum experiments should be made 

 within the antarctic circle to determine the law of diminution 

 of the force of gravity in the Southern Hemisphere. 



The present state of our knowledge leads to the belief that 

 the centre of gravity of the earth lies about three-tenths of 

 a mile to the north of the equator. Such a condition of 

 unsymmetrical balance of the earth, if it be established as a 

 fact, may enable us to account for that slow gyration of the 

 earth round an axis which is not the axis of the plane of the 

 ecliptic, which has now been discovered to be the case ; and 

 I earnestly hope that pendulum experiments may form an 

 integral part of the duties of the next antarctic expedi- 

 tion. 



The centre of gravity being north of the equator, the 

 plumb-line will be deflected there about 15" from the true 

 vertical, and astronomical observations by means of zenith 

 distances will need correction. This additional means of 

 measurement of the position of the centre of the earth's mass 

 will, no doubt, be resorted to, so that astronomical obser- 

 vations may check those made by the pendulum. 



The papers connected with the subject of a renewal of 

 antarctic research have been forwarded by the President of 

 the Eoyal Geographical Society to Sir James Hector for the 

 consideration of the Council of the New Zealand Institute, 

 with the expressed hope that they will use their influence with 

 the New Zealand Government to give favourable consideration 

 to the letters which have been addressed to their Agent- 

 General by the Eoyal Geographical Society, and referring to 



