FULGURITES—NEW SOUTH WALES. 379 
support to this positive element of Darwin’s view—is sufficiently 
indicated by the accompanying photograph taken by Mr. H. C. 
Russell, Government Astronomer. [A photograph kindly lent 
by Mr. Russell was exhibited.] The very numerous perforations 
of rocks, however, as, for example, on Little Ararat, reported by 
Abich® in 1869, is a sufficient proof that the same place is 
repeatedly struck. It is idle, therefore, to speculate, much more 
to dogmatise, on the question of the simultaneous production of 
any series of fulgurites. 
The fulgurites at the Kensington Sandhills were discovered by 
J. W. Grimshaw, and those at Bondi by J. M. Curran, by noticing 
the small pieces broken off where the tubes, through the wind 
shifting the sand, had been left exposed. <A little search then 
led to the discovery of the tubes themselves. They were dug 
out in the presence of two of us—J. W. Grimshaw and G. H. 
Knibbs—on two occasions, and J. W. Grimshaw and J. M. Curran 
on the other occasions. The bends and directions of the tubes were 
measured and are shown on the accompanying plate XIX, which 
also indicates the relative positions of the points where the tubes 
appeared on the surface. In form, the fulgurites are strikingly 
similar to those figured in plates 3 and 4, Band 55, and plate 4, 
Band 61, Gilbert’s Annalen ; and one piece shows the branching 
off of smaller tubes, so well illustrated in the plates mentioned. 
(See plate.) The fulgurites are by no means perpendicular, one 
being inclined as much as 42 degrees with the vertical. They 
vary from about 5 mm. to about 25 mm. in diameter, the thick- 
ness of the walls being also variable, but generally from 1-2 mm. 
Outside the tubes is a well-defined ring of reddish sand, the thick- 
ness of the band being about 3 mm.; the sand generally is 
siliceous, is quite free from calcareous matter, and is of a very pale 
yellow colour. A similar occurrence of reddish sand is noted by 
Fiedler (Gilb. Annal., Bd. 55, p. 133). In the opinion of one of 
us—J. M. Curran—this colour is derived by filtration from a 
stratum of limonite, which covered the sand-dune, and of which 
there is, in places, still a trace. Water passing through the 
limonite will, it is presumed, carry with it a small quantity of 
the hydrated ferric oxide ; this, trickling down the surface of the 
fulgurite, will strongly stain the sand immediately in contact. 
This view is not endorsed by another of us—G. H. Knibbs. In 
his opinion, the small trace of ferric oxide, to which the sand owes 
its yellow colour, was volatilised by the intense heat of fusion, and 
condensed in the sand immediately surrounding the fulgurite. 
There is no physical objection to this view, since even the heat of 
a porcelain furnace is equal, according to Elsner, to the task of 
volatilising ferric oxide. The distinctness of the boundary of the 
colour, a feature which is very striking, is urged as more consistent 
with the volatilisation than with the filtration view. Owing to 
