Shingle on the East Coasts of JS T eiv Zealand. 57 



13. One mile and a quarter west of the Bluff is the 

 entrance to the present harbour. To improve this, a few 

 years ago, two moles or jetties were run out into the sea. 

 As that on the east side of the entrance was being con- 

 structed the shingle, for a time, advanced with the work. 

 At last " the work got ahead of the shingle, which gathered 

 at a much slower rate ; but although the high-water line did 

 not advance, the shingle at low-water line was spreading 

 further out." The waves reflected from the work drove 

 back the shingle along the shore at the high- water line a 

 distance, at first, of about 800 yards, which gradually was 

 reduced to 500 yards. The shingle here accumulated for a 

 year or more, when " a very heavy north-easterly sea set 



into the bay," and this "accumulation of shingle, &c 



advanced right up to the mole within the space of two 

 days." 



14. Such was the end of this attempt to keep back the 

 shingle. The mole projects a less distance out than the 

 breakwater at Timaru does, but the result at Timaru must 

 in the end be similar, though it may take a longer time. 

 There is one other difference between the two cases. The 

 mole at Napier is sheltered from south-east seas, though the 

 swell is felt. The breakwater at Timaru is also sheltered 

 from the full force of heavy south-east seas, but sufficient 

 wave-action from that direction is felt to cause the shingle 

 to advance. It is difficult at present to estimate the 

 different results likely to ensue from this difference, but 

 it is not likely to alter much the final result, unless, in 

 the case of Timaru, the advance be more gradual than at 

 Napier. It may be remarked that, in the same way as at 

 Timaru, shingle is, in bad weather, thrown up on to the 

 mole at Napier, the top of which is also 6 feet above high- 

 water level. Not being cleared away, the shingle is washed 

 completely over the mole. 



15. After passing the entrance to the present Napier 

 harbour there is now a large accumulation of shingle, which 

 is mainly due to the shelter afforded by the western mole. 

 After this there is a long spit of shingle, the trend of which 

 gradually changes from north-west to north, enclosing a 

 large lagoon, called the Ahuriri Lake. The spit joins the 

 mainland four miles from Napier. Seven miles further on, 

 after enclosing another small lagoon, the beach ends at the 

 cliff before-mentioned. This cliff projects from the main- 

 land for about a mile, in an east-south-east direction. As 



