Minutes of Proceedings. 
vii 
Mr. J. H. Henkel, of the Forest Department, exhibited some tufts of 
a grass, Ehrharta villosa, Sch., growing on the sand-dunes, and aborted 
in a very singular manner through the agency of a species of Cecydomid 
fly not yet identified. The malformed part forms, however, such a thick 
covering that the insect, which is of a most delicate build, could not 
escape when reaching maturity were it not that the plant itself forced 
the partially aborted shoot tenanted by the larvae out of the malformed 
sheet and the midge is thus enabled to pupate and emerge in the open. 
An abstract of a Preliminary Note on the Diurnal Variation of Level 
at Kimberley," by Dr. J. E. Sutton, was read. This paper gives the 
preliminary results of observations made during the course of three years 
upon the variation of the level of the ground as recorded by a large 
horizontal pendulum of a special design made for the author by the 
Cambridge Instrument Company. It appears from the results that the 
movements in the surface of the ground which set up corresponding 
movements on the pendulum at Kimberley are very great. The maximum 
westerly elongation of the extremity of the pendulum occurs about 
5.30 a.m. ; the maximum easterly about 4.15 p.m. ; the median positions 
a little before 11 a.m. and 9.30 p.m. Geometrically these movements 
may be represented on the hypothesis that the hemisphere facing the 
sun bulges out, forming a sort of meniscus to the geosphere. The 
enormous rise and fall of the surface of the land that such a supposition 
would postulate are, however, mechanically difficult. It is curious that 
the range of the pendulum's excursion from west to east during the day is 
twice as great in winter as it is in summer. The author concludes from 
this that since the soil of Kimberley is usually very dry during the winter, 
the movements of water enclosed in the soil cannot be held responsible 
for the behaviour of the pendulum — as has sometimes been suggested. 
Not so much connection as might have been expected can be traced 
between the variations of weather and the movements of the pendulum. 
Barometric pressure variations and cloud are perhaps the most potent 
disturbers of the regular movements of the pendulum. In the years 
under discussion there was a strong tendency for the pendulum to 
deviate to the west of its mean position during the winter and to the 
east during the summer. This, if confirmed by subsequent observation, 
would indicate a response to the loading of the continent by rain on the 
east coast in summer and the west coast in winter, and to the unloading 
by evaporation in the opposite seasons. This point should be further 
investigated. 
