xvi Transactions of the Boyal Society of South Africa. 
possible that the Bush people had obtained it from the latter, but improved 
on it through their natural artistic disposition. He had at one time 
doubted the authorship of rock-graving in connection v^ith the Bush 
people, but he exhibited a Bush painting, in v^hich the back of the animals 
had been graved. The Bushman thus combined the two arts, graving and 
painting. An excellent instance of pictograph v^as shov^n in the shape of 
a snulf-gourd, decorated by an emissary of the Zulu Chief Dingaan, but who, 
however, died on his return journey, and in which were executed, in line 
poker-work, the most memorable things the envoy had noticed in CapeTown : 
a Dutch house, with its quaint gable ; a posse of cavalry and Government 
soldiers entering the gates of the Castle ; a Boer wagon ; gentlemen on 
horseback ; sportsmen firing at birds, with the pointer dog at attention ; 
the face of the large clock of the Dutch Reformed Church, and, lastly, a 
man with a very tall hat on playing the organ. The explanation of this 
pictograph is obvious. The Zulu could not have made his master under- 
stand things so extraordinary but by means of a delineation of the same. 
The question was further discussed of how far Bushmen drawings and 
carvings were to be looked upon as records of events, or as the expression 
of artistic skill ;per se; instances applying to the two hypotheses being 
quoted in turn. 
" On some Meteorological Conditions controlling Nocturnal Radiation," 
by J. R. Sutton. 
This paper contains the results of some hourly observations of radiation 
temperature made between sunset and midnight with two spirit ther- 
mometers, one lying upon, and the other supported on a stand five inches 
above a grass lawn ; with a discussion of the meteorological conditions 
that determine the differences of their readings. According to the results 
obtained, it appears that after allowance has been made for the state of the 
sky and the movement of the air, the only factor of real importance 
determining the radiation temperature gradient is the relative humidity. 
" The Resultant of a Set of Homogeneous Lineo-linear Equations," by 
Thomas Mum. 
Three different methods are given for obtaining the resultant, but the 
main interest is concentrated on one of them, because of two or three some- 
what obscure references made to it by Sylvester when studying the problem 
in 1863. Although Sylvester in one passage spoke of his researches as 
having been successful, and in another gave utterance to the most 
extravagant hopes regarding the fruitfulness of his result, he nevertheless 
did not proceed to publication, and after the year mentioned never once 
referred to the subject. The problem has also an interesting connection 
with bipartite functions. 
" On the Variation in the Value of the Atmospheric Electrical Potential 
with the Altitude," by W. A. Douglas Rudge. 
