512 Transactions. — Geology. 



the Lyttelton end, the lava-streams, ■when first passed through, were so wet 

 that the workmen could scarcely continue the work. In these streams all 

 the cellular cavities were either lined with sphserosiderite or filled with calcite. 

 Sixteen chains from the Lyttelton entrance, in the agglomerate bed No. 

 228, and from a fissure reaching from the roof of the tunnel, a copious 

 spring flows which has a constant temperature of 65" 20 degrees Fahrenheit, 

 consequently 12-20 degrees above the mean temperature of Christchurch — 

 about 53 degrees. Several eels have been caught near this spring in the 

 drain which runs from here to the mouth of the tunnel. There being no 

 connection with any other watercourse, these eels must have ascended by 

 the spring; they belong to the species Anrjuilla aucldancUi, Eich., and have 

 properly developed eyes. During the construction of the tunnel it was 

 frequently observed in the north, or Heathcote end, that the water rose in 

 the floor before a south-west gale, and subsided before the gale lulled ; no 

 observations could be made to ascertain whether the state of the tide had 

 anything to do with this. The height to which the water rose was some- 

 what under half an inch. After the earthquake of August 17, 1868, this 

 spring in the tunnel increased to such an extent that it laid the rails slightly 

 under water ; after a few days it decreased again to its former volume. 



Art, LXXXV. — Notes on a Salt Spring near Hokianga. By J. A. Pond. 



[Read before the Auckland Institute, 9th September, 1878.] 

 In looking over the Transactions of the New Zealand Institute, just to 

 hand, I read with pleasure the paper by W. Skey, on the Mineral Waters of 

 New Zealand, in which he gives the analyses and description of waters from 

 all known springs in the Colony. As we might expect, the North Island, 

 and particularly this district, has supplied the large majority of samples ; 

 but though much has been done in this respect there are very many springs 

 containing mineral salts, and having medicinal properties, which still remain 

 unexamined, and leave a rich field for those having the will and capacity to 

 bring them to light, or rather to the Transactions. 



Some mouths ago, Judge Monro first mentioned the existence of a salt 

 spring to me, and on a later occasion kindly placed a few ounces of the 

 water at my disposal, too small an amount to make a complete analysis of, 

 but as its especial characteristic was its saline nature, I have made a partial 

 quantitative analysis, which I give belov,-. 



