1921.] Caldwell and Marsden.—Inductive Interference. 
295 
high-grade machinery and care in the working-conditions. An extremely 
valuable and complete account of the whole subject from both the practical 
and theoretical points of view is given in a report issued by the Railroad 
Commission of the State of California on Inductive Interference between 
Electric Power and Communication Circuits This book, the investigation 
for which cost $100,000, must be consulted by all who are actually designing 
transmission-lines. The question as to whether in any particular case 
transpositions of the power circuit are advisable is given and answered by 
a consultation of the curves given on pages 1131, 1138, 1140, &c., of the 
report. 
With regard to breakdowns of the power circuits, these generally pro¬ 
duce to an acute degree the unbalanced conditions which, as we have seen, 
are so productive of interference. No means are available for preventing 
this type of interference, hence the importance of minimizing such occur¬ 
rences by high standards of construction, operation, and maintenance. 
In conclusion, we -wish to thank the various members of the Government 
Electrical Department for their kind and helpful interest in our experiments. 
STONE-SHANKED MAORI FISH-HOOKS. 
By Elsdom Best, Dominion Museum. 
The accompanying illustration' (fig. 1) shows the stone shank often 
employed by the Maori in former times in constructing his fish-hooks. 
The specimen has been carefully formed from a piece of slate stone, and 
all its surfaces have been smoothly ground. Its length is 2f in., and it 
is of the usual canoe-like form. The square-cut end has been reduced in 
order to accommodate the' lashing that secures the barbed point, which 
lashing also contains the feathers used as a lure. The line is passed 
through a hole in the other end, which is formed like the prow of a canoe. 
As ■ this form of hook has not been used by the Maori for many years, 
these stone shanks have puzzled many persons. The specimen illustrated 
was mounted by a Nukutaurua native. 
These curiously formed stone shanks for fish-hooks formerly employed 
by the Maori in his sea-fishing operations were often carefully fashioned 
and finished, the surfaces being ground smooth. Many of them were made 
from a kind of slate, but other forms of stone were employed. The use 
of these implements must have been fairly universal throughout both 
Islands, inasmuch as they have been found at many places from the North 
Cape southward to Eoveaux Strait. Occasionally one formed of green¬ 
stone (nephrite) has been found, but these are rare, as also are greenstone 
points or barbs. It is of some interest to note that many natives of the 
present day are quite ignorant of their use : some assert that they were 
employed in certain ritual performances, and one, aged seventy or there¬ 
abouts, had the hardihood to assure me that they are ear-pendants ! 
The shank shown in fig. 2 is from Otago. It is an unusually large one, 
being 54 in. in length, the material being a reddish mudstone. The 
native from whom it was obtained by Mr. Milligan, of Wellington, did 
not know the use of the implement. In cross-section it is of the usual 
triangular form, with the sides rounded. The flatter side is but slightly 
convex traversely, but markedly so longitudinally, an unusual feature. 
The pointed end, to which the line was attached, is, as usual, formed like 
