416 Transactions. — Geology. 



but it is easy to suppose the eastern part to have filled up with a deposit of 

 sand, to have become dry ground and supported vegetation, which after- 

 wards gave way to the effects of wind or fires during a dry season, when 

 the water again took possession, the sand being driven to leeward to form 

 sand-hills. The Wairarapa or the Canterbury Plains offer peculiar ad- 

 vantages for the formation of wind-formed lakes when the condition of a 

 sandy soil is present. The north-west wind descending obliquely from 

 mountains, with accelerated force through certain gullies, has a swooping 

 action, which of course cannot affect the gravels and clays, but if it meets 

 with sand can soon make a hollow for the reception of water. If this 

 hollow should be in a position to be filled by storm-water, springs, or 

 neighbouring streams, it becomes a lake, or possibly a swamp. 



The nature of the surrounding soil must also be such that the access of 

 water to the hollow shall not be able to cut a channel of egress for it, 

 otherwise the lake will be drained from natural causes. 



I place Burnham Water as a typical example of a wind-formed lake, and 

 there is also a small lake below my house, which I have called the Miramar 

 Lagoon, which had every appearance of being a permanent lake when the 

 settlers arrived in the district. Since that time, from the destruction of the 

 flax and other vegetation which surrounded it, it has undergone many 

 changes, and is now generally dry in summer time. 



There is another mode of wind-formation of small lakes which I have 

 observed, viz., by sand blowing across the mouth of a gully and damming 

 back the water. This sort of lake gradually fills up with sediment, and 

 eventually becomes a swamp, and, later on, di-y ground. There are several 

 examples of this sort of lake on the peninsula of Hataitai, in the different 

 processes of lake, swamp, and dry ground. 



Aet. LXVIII.— 0;i BidwiWs Front Hills. By J. C. Crawford, F.G.B. 

 [Read before the Wellington Philosophical Society, 10th January, 1880.] 

 There is a low range of hills, about seven or eight miles in length by about 

 one mile in breadth, down which the road runs from the Featherston and 

 Waihenga Ferry road to Mr. Bidwill's house, which forms an interesting 

 meter of the immense work which the action of rain and rivers has per- 

 formed in the Wairarapa Valley. 



This range separates the low part of the valley to the westward towards 

 Featherston, from the equally low part on the east containing the river flats 

 of the Huamahunga and the Wharekaka Plains. The height of these low 



