108 Transactions. 
_ Since the aneroid barometer came into use barometrical measurements of 
altitude have become very common, but I am not aware of any scientific work 
in which the subject is treated at all fully. 
The officers of the United States Survey, engaged on the survey of the 
western slopes of the North American continent, are reported to have made 
careful and elaborate investigations, and to have constructed hypsometrical 
tables suitable for all altitudes above the sea-level, but I have not been able to 
obtain any work containing an account of the results they have arrived at. 
Whether facts similar to those I have detailed above have been previously 
noted I have not been able to discover, and my chief object in presenting 
these notes to the Society is, if possible, to elicit information on the subject. 
Art. VIII.—On the Reclamation of Land devastated by the Encroachment 
of Sand. By ©. D, Wurtcompr. 
[Read before the Wellington Philosophical Society, 25th September, 1872.] 
THE subject of reclaiming land devasted by the encroachment of sand is 
one of the greatest importance to the settlement of Taranaki ; in fact, to 
the west coast of this island in general, if not to the eastern portion of it. 
Tt is now admitted that the bars at the mouths of rivers are principally 
formed of sand driven along the coast or washed in by the sea ; that where 
there is a bar it will be found that the soil is loose, both at the bottom and on 
the sides where the river discharges; and that with rocky bottom and sides 
there is generally no bar. 
At New Plymouth we have a drift following the prevailing current and 
set of the tide, from north to south and from south to north we have the 
_ Shore drift blown along coastwise by the prevailing winds ; besides these, there 
is the large amount of detritus carried down every river by every rain, and 
which is in¢reased to a maximum by the process of first clearing a loose 
virgin soil. These three operations combined must tend to create and main- 
tain bars, generally of a horse-shoe shape, at the mouths of our rivers (unless 
the tidal pressure is transverse to the flow of the river, and 
than this latter), infinitely to the prejudice of navigation, 
Again, the effect of the drifting of sand in large quantities is gradually to 
choke up the smaller streams, backing their waters, and causing the formation 
of swamps and marshes along the line of their course ; and finally, if left 
unchecked, the sand drifts further and further inlan 
areas of desert land. Anyone who has observed the rapid encroachment of 
the sand in this province, will at once own that within very few years damage 
has been done to an enormous extent in all the three modes pointed out 
much stronger 
d, creating ever-increasing 
