S16 R. H. Hammer sley-Heenan, C.E. — A Short [Nov. 28, 



wj lot to show that not only is greenheart attacked by the ordinary 

 worm in this country, but that it is also a victim to the ravages of the 

 Chelura terebrans, and I believe also to the Limnoria itself. 



About the year 1878 the Port Elizabeth Harbour Commissioners 

 had two Jetties constructed, from the designs and under the profes- 

 sional direciion of Sir John Coode, Mem. Inst. C.E. For the most part 

 wrought iron was used, but it was decided that the seaward ends, 

 known as the V heads, should be — for special reasons — of wood, and 

 after due consideration greenheart was selected as the timber most 

 suitable for the purpose, and with this material — excellent of its kind 

 — the work was carried out. 



Some time ago, I had to make a detailed inspection of these Jetties, 

 and on examining the V heads, I noticed what at first appeared to 

 be signs of decay in one of the horizontal pieces, and, on cutting 

 into it with an ' adze, found it completely honeycombed — for about 

 an inch deep, with the tunnels of the Teredo, and, on further 

 examination, found that all the horizontal timbers — at low water 

 mark — had been in a like manner attacked. I then looked to the 

 vertical pieces — or piles — and discovered that although the worm 

 had entered many of them, still the progress it had made was small, 

 compared to that on the horizontal pieces. 



Having completed my inspection of this portion of the structure, 

 and having satisfied myself that the Teredo was in undoubted and 

 secure possession, where it will unquestionably remain until it has 

 completed its work of destruction, I proceeded to examine the 

 timber frame — also of greenheart — that has been placed outside 

 the iron portion of the Jetties to act as a fender to prevent boats 

 coming into direct contact with the iron. I there found not only 

 the Teredo — evidently thoroughly enjoying itself, but also, in vast 

 numbers, a most destructive little creature which I believe to be 

 the Chelura terebrans, which does not attack the timber in the 

 general and haphazard way in which the Teredo appears to do, but 

 invariably commences its work at the ends of the timber, or where 

 one piece comes into contact with another, and in this way — although 

 the actual area destroyed by it is comparatively small — it becomes 

 more injurious to a framed structure than is its great competitor. 

 To more clearly explain what I wish to convey, I give a simple 

 sketch — in plan — showing what I actually foiuid on the day in 

 ^question. The shading represents the portions destroyed by the 

 Chelura. 



