946 
FOREST AND STREAM. 
[Dec. io, 19x0. 
passed amending all deeds of gift covering 
championship trophies in the five different 
classes of speed boats and cruisers. Hereto¬ 
fore it has been stipulated that contests for 
these trophies be held on the Hudson River, 
and the amendment now includes the waters of 
Long Island Sound. This action was taken be¬ 
cause of conditions on the Hudson River dur¬ 
ing September last, at which time the course 
was so full of floating logs and debris, it was 
almost impossible for racing boats to avoid 
serious injury. It is quite possible that next 
year, if similar conditions obtain, the National 
Motor Boat Carnival will be held on Long 
Island Sound. 
Canoeing. 
Some Observations on the Art of 
Building & Yacht. 
“Nature never makes a mistake in a me¬ 
chanical contrivance.” As this quotation is 
from Hugh Miller, and as this paper has to 
refer in part to the study of ichthyology and 
hydromechanics, I must be particular in stating 
that it is not my intention to discuss these sub¬ 
jects as a trained scientist. I have no pre¬ 
tentions to being able to do more than to 
furnish observations and to record experiences 
which might lead to a more thorough investiga¬ 
tion of the matter with which I propose to deal. 
The object I have in view is to endeavor to 
explain what appears in nature to be the hydro¬ 
mechanical surface of least resistance, or, in 
other words, nature's method of preventing the 
continuity of cohesion which exists in water 
from holding a moving body in check. That in 
one particular there is a more complete adapta¬ 
tion of the creature to its environment than has 
hitherto been recognized, my observations lead 
me to believe; but, so far as ichthyology is 
alluded to, I refer solely to the structural de¬ 
velopments which appear upon the cuticle 
coverings of marine fauna; and where hydro¬ 
mechanics are concerned, the reference is en¬ 
tirely confined to surface construction and not 
to the “solid” of least x resistance. This sub¬ 
ject and the wave system have been so thor¬ 
oughly examined and explained by the late John 
Scott Russell that it is only necessary to quote 
him as an authority for the purpose of stating 
that he did not deal with surface construction 
further than incidentally to remark that in re¬ 
gard to the paradoxical laws which govern the 
movements of water, little was known on the 
subject. As a toiler of the sea. I have had the 
advantage of experiencing the lar-reaching re¬ 
sults of what he has accomplished in regard to 
the solid of least resistance and the correctness 
of his theory in this particular; but before his 
experiments were made, marine architects be¬ 
lieved positively that vessels should not be con¬ 
structed with sharp wedge-shaped bows, but 
should be made to resemble the head and 
shoulders of a codfish. 
Water, however, is unlike those substances 
where the component parts are in a fixed posi¬ 
tion; being a fluid, it yields to pressure when 
separation is in process without becoming de¬ 
formed. This being the case, the law of ad¬ 
hesion and cohesion which exists in water 
comes into operation when a solid body is pro¬ 
pelled through it and holds it in check. This 
matter has already been thoroughly examined 
and explained by scientists, but I must here 
reier to it in order to call attention to one 
particular fact in connection with it which does 
not appear to have been observed or explained. 
To enable the reader to understand better what 
I wish to express, I shall put it in the form 
of a simile. When a nail is driven into wood, 
the smoother the nail is the less power it re¬ 
quires to drive it, but this principle will not 
apply to a solid body when it is driven through 
water. It therefore becomes reasonable to sup¬ 
pose that the surface of the solid of least re¬ 
sistance must be of different construction in 
some particular when wood and water are 
separated. Nature, however, seems to have 
recognized this fact and to have provided for it 
by evolving for marine creatures a surface sys¬ 
tem which during movement prevents the par¬ 
ticles of water from adhering to them and co¬ 
hering to each other, for if it were otherwise 
their locomotion would be retarded. As it 
may be assumed that under similar conditions 
an artificial surface would produce the same re¬ 
sults as a natural one when both were con¬ 
structed alike, 1 shall endeavor to describe the 
appearance of the natural surface, and also to 
offer an explanation in regard to the reason 
why nature has adopted a method which is con¬ 
trary to that which is supposed to be correct. 
But before doing so I shall narrate an incident, 
the bona tides of which I can vouch for, and 
which is illustrative of the problem under con¬ 
sideration. 
A friend of mine whb, being a great sports¬ 
man, was anxious to possess for shooting pur¬ 
poses the most perfect canoe that could be 
built, and knowing that the best lines of con¬ 
struction for combining lightness of draft, speed, 
and carrying capacity, were to be found by 
imitating the graceful form of an Indian bifch- 
bark canoe, he had his made on that model. 
As it was constructed of thin cedar boards, he 
conceived the idea that he could greatly im¬ 
prove on birchbark by making the exterior 
much smoother than the bark, which is relative¬ 
ly rough and uneven compared to a surface 
which has been made smooth by polished 
varnish. He therefore put on several coats of 
copal varnish and polished it with pumicestone. 
But there never was a sportsman more disap¬ 
pointed with the results of an experiment than 
he was. The canoe was the slowest and most 
difficult to paddle that he had ever been in. It 
dragged so much water that it tired him out. 
He then became impressed with the idea that 
water had a magnetic attraction for copal 
varnish, and. acting on this absurd notion, he 
had the varnish carefully scraped off and sub¬ 
stituted for it a coating of common rough paint. 
The result was a great success, for the canoe 
fulfilled all his expectations and he became con¬ 
vinced that the magnetic attraction theory was 
a correct solution of the problem. Now, to a 
mere novice in the study of natural history the 
idea suggests itself that, if my friend had, in the 
first instance, imprinted on the wood of his 
canoe a pattern like the shagreen of a shark’s 
skin or one resembling the “rough bossed” 
covering which appears on the costal epidermis 
of an alligator and had varnished over it, he 
would have made a more natural surface and 
also one which, if the paint was better than the 
polished varnish, would have given better re¬ 
sults than either. But here we have to face a 
paradox which becomes the more perplexing 
when we take into consideration the fact that 
what is called the shagreen roughness of the 
shark's skin is in reality the most even part of 
the covering; for, besides this dermal deficiency 
of evenness, we find other formations in the 
shape of papillae and ossified scutes. It goes 
without saying that, if an orthodox mechanical 
engineer were to notice on the smooth sides 
of a yacht a pattern showing a surface similar 
to those referred to, he would state positively 
that the yacht could never win a race, and yet 
the shark is a fish or mammal of remarkable 
speed, notwithstanding these apparent obstruc¬ 
tions to rapid movement, and being a pelagic 
traveler would require a surface which would 
not impede the power of propulsion. The 
shark, however, is only one instance of many 
others where dermal developments are to be 
found and where they are accompanied by great 
rapidity of locomotion. It so frequently oc¬ 
curs in the species of other genera that struc¬ 
tural design of surface and speed are combined, 
that it is reasonable to suppose there is rela¬ 
tion between them. It could not, however, be 
expected that structural design of surface would 
insure great speed where the bodily formation 
is not adapted for separating the water. The 
turtle genus, for instance, are remarkable for 
two things: the structural designs which appear 
on their armored coverings, and the fact that 
they can paddle themselves so rapidly through 
the water though they are ill adapted for divid¬ 
ing it. 
On the other hand, the ganoids show cuticle 
structures which are-equally as prominent, and 
they possess extraordinary speed, that of the 
garpike having been described by naturalists as 
unsurpassed. This genus, being partly reptilian, 
are also protected by armor, but the patterns 
of the cuirass vary in form on the different 
species, as they do on the turtle family. But 
though these structural developments differ in 
pattern they agree in one particular—they are 
all smooth, but not even; and as this feature of 
smooth unevenness appears in the species of 
other genera where there is no armored covering, 
the inference would be that an object was to be 
gained by the adoption of a contrivance. I 
need not here refer to those instances where 
there is no sculptured design of surface. 1 shall 
do so elsewhere. It may, however, be remarked 
that in such cases the power of sustaining rapid 
movement is not so great as it is where we find 
cuticle development, and where there is armored 
covering like the slated roof pattern of some 
ganoids there could not be an exudation of 
slimy matter. 
The turtle family show an uneven surface in 
some species by the individual convexity of the 
shields; in others the shields are imbricate; still 
others have the “rough bossed” skin with 
vertebral shields which are convex. The 
ganoids show the same system. In some 
species the scales are rhomboidal; in others 
the plates are imbricate and sufficiently thick 
to produce unevenness where they overlap; still 
others have “longitudinal rows of bony scutes,” 1 
some of which extend from the head to the 
caudal fin, the intervening spaces being what 
has been called rough. Naturalists in using the 
phrase “rough bossed” and the word “rough” as 
descriptive of the cuticle coverings of marine 
fauna have, I believe, done so more to desig¬ 
nate a pattern than to convey the idea that 
there is such a thing as a rough covering, if we 
accept the meaning of the word rough in its 
ordinary sense. 
Two instances where the word rough has 
been applied to these coverings will enable the 
reader to appreciate the point I wish to make. 
The swordfish and the dogfish are included in 
this classification, and they represent two 
species which are the fastest swimming fish we 
know of. The covering of the latter appears 
to be very rough to any one who is not look¬ 
ing for evidence in support of a general prin¬ 
ciple. But if we examine the skin carefully we 
find it represents a pattern of unevenness which 
shows on it no sharp edges which would drag 
the water. The unevenness, however, is so ap¬ 
parent that it requires no magnifying lense to 
observe it, and it has come into special use 
for covering the handles of swords, in .order 
to give a firm grip to the palm of the hand. 
Strange to say, the speed ot this species of 
shark is so phenomenal that a Nova Scotia 
fisherman will tell you that a dogfish can go 
through the strongest net with as much ease 
as a cannon ball can be fired through a barn 
door. 
[to be concluded.] 
1 This allusion is to the sturgeon, one of the fastest of 
the ganoids. 
A. C. A. Membership. 
new members proposed. 
Atlantic Division.—James H. Calisch, 192 
Woodworth avenue, Yonkers, N. Y., by U. M. 
Van Varick. 
Western Division.—Bill F. Sykes, Rockford, 
Ill., by Ralph E. Penfield. 
MEMBER REINSTATED. 
Western Division.—5071, Frank W. Friedland, 
505 North Clark street, Chicago, Ill.; 5233, 
Ralph E. Penfield, 324 North Main street, Rock¬ 
ford, Ill.; 5386, George C. McLean, 322 North 
Main street, Rockford, Ill. 
The Forest and Stream may be obtained from 
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supply you regularly. 
