ARTIFICIAL EARTH SCULPTURE

Timaru Herald, Volume L, Issue 4822, 19 April 1890, Page 4

ARTIFICIAL EARTH SCULPTURE-

In an article nnder this heading m Zealand) a Mr W. IN. Blair, the well-known civil engineer, treats of the Amount of work done, directly and indirectly, by the miner and the navvy m " sculpturing " the surface of .New Zealand. His references to work done (at Timarn will make the article of greater interest to people m this district. As to the " earth sculptnre " of the miner, some 14,000 men have, sayo Mr Blair, been cutting and carving at New Zealand for nearly thirtw years, and have shifted materials enough to " fill up t^ie harbours of Lyttelton and Dunedin right to the heads, or put eight inches of soil on the whole of the Canterbury Plaint." The navvy, according to Mr Blair, has only done about a fiftieth of the work which has been accomplished by the miner ; but if we include m the operations of tha navvy the construction of harbours, it will be seen that bU influence on the physiography of the country is very considerable. Indeed, Mr Blair expresely refers to this when Le speaks of the check that is sometimes placed upon " the travel of the beaches by solid ietties of break wuters." As he says, "all up tho two coasts o' New Zealand — from south to north — there is a decided, intermittent, beach trave!, varying only m its velocity. Tho prevailing seaa from the southwards strike the const obliquely, and drive the shingle and sand before them with 3 zigzig motion, tha speed of which is regulated by the force of' the seas and the angle at which they touch the aliore. Occasionally, when the wicd is northerly, the beach remains stationary, or goeß a little backward, but theea exceptions do not affect the general result — a decided movement northwards .Experiments show the travel of shingle at Timaru to go up to a mile, and, Bt the Wairau to five chains per day " With tbe operations of the Bettler, the miner, and tho weatber constantly affecting the country of the interior ; with the rivers carrying vast quantities of " shifted " material to the sea, and with tha beach travel constantly carrying the debriß and sediment northward, we can understand how it is that "Farewell Spit is growing visibly," and bow by and by, " it will reach across to D'Orville Island, and convert Tasman Bay into an inland sea. In the meantime works like breakwaters not only intercept the travel of the shingle m some instances, but lead to other considerable results. For example, as Mr Blair says, " at Timaru the construction of the breakwater has, m nine years, intercepted the travel of about 1,200,000 cubic yards of shingle. This shingle m its courso formed a natural protection to thn coast, but as sonn as the &ow was interrupted the sea encroached rapidly on the land north of the breakwater, and caused great damage" ; and, says Mr Blair, " it his been neccuary to expend about £8300 m forming an artificial beach to protect the railway which skirts the shore." The breakwater at New Plymouth had led to eimilar results ; but, our interesting physiographer informs ÜB, " Oamaru has nothing to fear, becaufe it is south of the Waitaki, the first shingle carrying river ; and tho West Coast coal harbours are safe, becsuso the large rivers on which they are situated will scour away any accumulation formed by the sea."