SEPTEMBER 14, 1899] 
NATURE 
401 
The idea of a photograph ofa thunder wave is a pleasing fancy, 
at all events. 
It seems to me that it will be impossible to formulate even a 
reasonable guess as to the cause of these dark flashes until a 
good many pictures are brought together for comparison, and as 
much testimony as possible secured as to the appearance of the 
flashes to the eye. Personally I have seen very few of the 
pictures, and never the original negative. 
My intention in writing this letter is not so much to advance 
theories accounting for the phenomenon of the dark-flash as to 
reawaken an interest in the subject, and bring out ideas from 
persons qualified to treat the matter. 
Madison, Wisconsin, U.S.A. R. W. Woop. 
Tides in the Bay of Fundy. 
In the last report of Mr. W. Bell Dawson on the Survey of 
Tides and Currents in Canadian Waters, the results are given of 
an investigation of the tides in the Bay of Fundy. The inform- 
ation in Mr. Dawson’s report is interesting, as these tides are 
frequently credited as having the greatest range of any in the 
world, and in some books of physical geography are stated as 
having a range of 120 feet,4 or more than double that which 
actually prevails. 
As a matter of fact the range of the tides in the Bay of 
Fundy does not exceed that which occurs in the Bristol Channel, 
where the extreme recorded difference between high and low 
water at Chepstow is 53 feet, being the same as the “Saxby,” 
or record tide in the Cumberland Basin, Nova Scotia. The 
cise above the mean level of the sea in both cases is about the 
same, or from 22 to 23 feet. 
In the Bay of Fundy the range varies considerably at different 
localities. Outside the bay at Portland on the north side the 
range is 9} feet, and at Cape Sable on the south side $3 feet. In the 
Atlantic, on the south side of Nova Scotia, the range is from 6 to 
7 feet. At the mouth of the bay at Yarmouth the range is 16 feet, 
and at Seal Island 18 feet. Further up, at Digby, on the south 
side, and St. John on the north, it increases to 27 feet. Where 
the bay divides above Black Rock the range is 36 feet. In the 
Minas Basin it varies from 41 feet at Parsboro to 48 feet at 
florton Bluff and 504 feet at Noel Bay. In the Chignecto 
Channel in Cumberland Bay the range is 454 feet. 
From observations obtained by tide gauges fixed at different 
stations, and information collected in the localities, Mr. Dawson 
gives the range of spring tides as follows. 
The highest recorded tide is known as the ‘‘Saxby tide,” 
which occurred in 1869. The low water mark for that tide is 
mot given, but taking the lowest low water level recorded, the 
range of that tide in Cumberland Bay was 52°80 feet; the 
ordinary spring tide range there being 45°80 feet. The 
Admiralty tide tables give this as 45} feet. 
At Moncton, the Saxby tide rose above the lowest recorded 
level, 38°34 feet; the next highest recorded tide being in 1887, 
31-91 feet. An ordinary spring tide rises 30°25 feet above mean 
low water of spring tides. The Admiralty tide tables give the 
range at Moncton Railway as 47 feet. Mr. Dawson points 
out that this is misleading, this range being that above low 
water at the mouth of the river, from which the low water 
line has a considerable inclination towards the head of the 
estuary. 
At Parsboro, in the Minas Basin, the ordinary spring tide 
range is 41 feet, and the extreme 47 feet ; the Admiralty tide 
tables giving the ordinary range as 43 feet. 
Mr. Murphy, the Provincial Engineer of Nova Scotia, in a 
paper contributed in 1867 to the Institute of Natural Science, 
on the tides in the Bay of Fundy, gave the range of spring 
tides at the head of the bay as 22 feet above mean sea 
level, and as varying from 50 to 60 feet above extreme low 
water. 
Having a few years since to report on some proposed em- 
bankment works in the Bay of Minas, I made inquiries in the 
locality from those best able to furnish me with information as 
1JIn Sir J. F. Herschell’s ‘‘ Physical Geography of the Earth,” fifth 
edition, 1875, it is stated that: “In the Bay of Fundy the tide not uncom- 
monly rises 50 feet, and, as is said, on some occasions to more than double 
this height.'* Robinson, in his ‘* Mechanical Philosophy,” in the article on 
Tides, says, “‘In the Bay of Fundy, in the harbour of Annapolis Royal 
the tide rises 120 feet.’ 
NO. 1559, VOL. 60] 
to the rise of the tides there, and came to the conclusion that 
at Horton the greatest range to be dealt with was 48°50 feet. 
The difference in the range of the tides in Cumberland Bay, 
at the head of the Bay of Fundy, and in Verte Bay, North. 
umberland Straits, in the Gulf of St. Lawrence, is worth 
recording. The length of the isthmus which separates the two 
bays along the line of the proposed Chignecto Ship Railway is 
eighteen miles. The range of ordinary spring tides on the one 
side of this neck of land is 45°80 feet, and of the highest 
known tide 52°80 feet; and on the other side 13°40 feet and 
560 feet respectively, the mean level of the sea being only 
0°26 feet higher in the Cumberland Bay than in Bay Verte. 
It is interesting to compare the tides in the Bay of Fundy 
with those in the Bristol Channel. At Bude Haven and Pem- 
broke, at the mouth of the Channel, the rise of an ordinary 
spring tide is 23 feet ; at the mouth of the Avon it is 4o feet ; 
at Chepstow the range is 50 feet, and in extreme tides 53 
feet, the rise above the mean level of the sea being 233 feet. 
From levels taken across the land from Portishead in the Bristol 
Channel to Axmouth in the English Channel, with a mean tide 
rising 354 feet at Portishead and 10 feet at Axmouth, the mean 
level of the sea was found to be 9 inches higher at the former 
than at the latter place.! 
There is a tidal bore in the Bay of Fundy, but it is not so 
strongly developed as at some other places. It shows itself at 
Moncton, 19 miles from the mouth of the Petticodiac River, 
where the estuary consists, at low tide, of mud banks and 
flats, with a low water channel about 500 feet wide, and 
having at high water a width of half a mile. The run 
of the rising tide first breaks into a bore at Stoney Creek, 
8 miles below Moncton, and continues to the head of 
the estuary at Salisbury, 13 miles above, the total dis- 
tance traversed being 21 miles. Mr. Dawson describes the 
noise made by the approaching bore as that of a distant train, | 
which increased to the hissing and rushing sound of broken 
water. The bore arrived at the point of observation eleven 
minutes after the sound was first heard, having the appearance 
of a front of broken and foaming water 2 to 3 feet in height. 
The mean velocity was 8°47 miles an hour, the maximum being 
9°61 miles. The greatest rise of water after the bore passed 
was 3 feet in ten minutes. The greatest recorded height of the 
bore is 5 feet 4 inches. 
The only other place in the bay in which a bore has been 
observed is in the upper part of Cobequid Bay. 
W. H. WHEELER. 
ETHNOGRAPHICAL COLLECTIONS IN 
GERMANY. 
(ps2 question of the representation of primitive 
culture in our national museums is rapidly be- 
coming an urgent one, not only on account of the 
growing importance of anthropology, but also because 
primitive culture itself is disappearing before civilisation. 
The wild man is dying out or being transformed, and 
the hours during which we may question him about 
himself are already limited. Those nations therefore 
which take the utmost advantage of the opportunities 
which remain will have something in the nature of a 
monopoly when primitive culture is actually extinct ; and 
it is to them that the students of the twentieth century 
will have to apply for their facts. 
If her present rate of progress is maintained, Germany 
will soon have so far distanced all other European 
countries as to place herself in a position of permanent 
and unassailable superiority. It cannot therefore but be 
a matter of importance to cast a glance at the present 
state of ethnographical museums in Germany, in order 
that we may form some notion of the relative position of 
our own. 
Almost all the large cities in the German Empire 
possess ethnographical collections, and in such places as 
Leipzig, Dresden and Hamburg, these are of first-rate 
1 ‘*Tidal Rivers.” (Longman’s Engineering Series, 1893.) 
