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. YIII. — On the Reclamation of Land devastated hy the Encroachment 

 of Sand. By C. D. Whitcombe. 



[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 increased 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 much stronger 

 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 inland, creating ever-increasing 

 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 



