300 
The N.Z. Journal of Science and Technology. [July 
Section 3.—Chemistry, Physics, and Engineering. 
An Improved Planisphere, by D. M. Y. Sommerville. 
(This paper appeared in t]je May number of this Journal, pp. 193-05.) 
Tables of Mathematical Functions, by C. E. Adams. 
Press Notice ( Lyttelton Times). 
Dr. 0. E. Adams, Government Astronomer, Wellington, gave a lecture on “ Tables 
of Mathematical Functions.” He said that he had been led to construct the tables 
by a request for help from Mr. Evan Parry,* recently Government Electrical Engineer 
in New Zealand, who found that the ordinary tables of natural logarithms were not 
sufficiently minute for his practical use in electrical work. Mr. Parry had assured him 
that tables of that character were required by electrical engineers generally. 
Mr. Powell said that the tables were of very high value, and that Dr. Adams 
should be congratulated on his work. The lecture was further discussed. 
The Leather Industry, by A. V. Mountford. 
Press Notice ( Lyttelton Times). 
Mr. A. V. Mountford, Christchurch, read a paper on the manufacture of leather, 
which he said was one of the earliest human arts. He sketched the early history of the 
industry. Many of the present methods, he said, were the result of thousands of years’ 
experience, and they had been developed mainly by the ingenuity and judgment of 
uneducated workmen. It was regrettable that the scientific principles underlying the 
industry were very imperfectly understood. The industry, in its modern developments, 
was greatly indebted to botany and chemistry in the discovery of an abundant quantity 
of tanning-materials. Science also had led to economy in labour and in the use of 
materials. Mr. Mountford showed the physical structure of skin, and described the 
principal processes of manufacture. 
The North-west Winds of Canterbury, by H. F. Skey. 
The origin of the usual high temperature of the north-west winds on 
the Plains is of considerable interest. The thermodynamic explanation is 
probably chiefly that of a fohn wind, but it seems to the writer that a 
considerable amount of kinetic energy of the wind runs down into heat 
during the passage of the Southern Alps and their wide extent of foothills. 
This heat and the latent heat of precipitation on the passage are sufficient 
to account for the phenomenon. Thus a comparatively moist north-west 
wind is assumed to come off the Tasman Sea and to be is forced over 
the ranges. As it rises, its temperature and pressure diminish and its 
degree of humidity rises. After it attains the dew-point clouds are 
formed and rain is precipitated, and a very large part of the latent heat 
passes into the air, which remains saturated at a higher temperature 
but at the same pressure, as if no condensation and no frictional heating 
had occurred. 
When this air descends the eastern slopes of the ranges it is compressed 
as it descends, its degree of humidity decreases and its temperature rises 
as work is performed on it, and in virtue of the heat of condensation, &c., 
which it has absorbed its temperature must be much above what it was 
at an equal altitude before it crossed the ranges. 
* E. Parry, The Electrical Properties of Three-phase Transmission-lines, this 
Journal, p. 127, March, 1919. 
