818 
FOREST » AND STREAM. 
! ' * |T JDec 17, 1904. 
Horsepower Rating. 
BY A. E. POTTER. 
The recent adoption by the English Marine Motor 
Association of the rule that all horsepower rating shall 
pe based on actual fuel consumption, marks a decidedly 
important step in the development of carburation and 
other important points in design, construction and 
operation of marine gasolene engines. One pint of 
gasolene consumed in one hour, constitutes one horse- 
power. This is their new rule. 
The recent. ruling of the American Power Boat As- 
sociation that all engines should have a speedometer 
attached, was evidence of the unsatisfactory rule for 
horsepower rating employed here last summer. 
■ The average American-built marine gasolene engine 
does not use gasolene as economically as it ought. This 
is well known throughout the trade. Some engines are 
designed to secure favorable ratings by means of dif- 
recent proportions and speeds, without reference to the 
amount of fuel used. 
The great advantage of a consumption of fuel rating 
would he in its relation to the perfection of carburet- 
tmg apparatus. When we come to study the cata- 
logues of various engines of both types, we find the 
consumption of fuel per horsepower is often entirely 
ignored, and in some cases grossly exaggerated. For 
instance, one manufacturer may claim that his engine 
will develop a certain horsepower at a consumption of 
less than one pint per hour. It may be true that their 
engines have been operated honestly at a certain speed 
within a limit of one pint, while at an increased or de- 
creased speed the variation would be considerable 
either way. When I say honestly, I refer to a brake 
test conducted in a strictly practical and intelligent 
manner, the speed of the engine being known, not 
guessed at. A case in point: An engine is run at 650 
r. p. m., and has a net pull on a 5ft. brake beam of 
i81bs. The brake horsepower would figure 11. 1384. 
In case the speed was estimated at 800 — and it is a 
very hard matter for any one to estimate accurately at 
any such speed— the horsepower would figure 13.7088. 
This same engine would probably not show the same 
fuel consumption per horsepower at different speeds, 
dep'ending, among other things, on the amount of 
power absorbed by the engine and cooling water, in- 
creased or decreased volume of each charge in turn 
depending on the temperature of incoming gas, the 
frictional resistance at both inlet and exhaust, muf- 
fling, leaks in valves and past the rings, tension of 
valve springs, lift of valves, timing of opening and 
closing, perfection in carburation, regularity, speed, etc. 
It will be an incentive to the modern student to care- 
fully go over his work comparatively with that of other 
designers, proving his work and ideas in obtaining best 
results. It will weed out the dreamer, the bungler, the 
follower and crank, and give due credit to the man 
who can demonstrate his ability to furnish a superior 
article in the line of marine gasolene engines. Scien- 
tifically and practically, it ought to tend to perfect gas 
engine design and construction fully equal with that 
attained by the steam engine. 
There is a class who continually harp that no im- 
provements can be made in the four-cycle engine, that 
all theories have been carefully worked out and proven. 
It is my opinion, based upon a long study of the ex- 
plosive engine, that the next few years will prove con- 
clusively that absolute perfection in the explosive en- 
gine will probably never be reached. 
With the increased consumption of gasolene from the 
use of the gas engine, its price must steadily advance. 
While at present we seem to care little for the expense 
of operation, in countries such as Australia, where the 
price is 75 cents, they "count the cost." 
Queries on Marine Motors* 
J. A. B., Southampton, Eng.— Have just received Forest and 
Stream dated Nov. 12, and wish to avail myself of your inquiry 
department. What carburetting system is considered the most 
economical for two-stroke engines? My engine uses at least 
50 per cent, more petrol than a neighbor's, both engines made 
by the same manufacturer and same dimensions. Is this hot 
unusual? 
Ans. — It is usually considered that float feed car- 
buretors are more economical than vaporizing valves, 
but comparative economy tests will show great varia- 
tion. Sufficient attention is not paid to fuel consump- 
tion. At five times the price, it would stand one in 
hand to watch out. 2. It is not unusual for two differ- 
ent makes of same sized two-stroke, or, as they are 
called, two-cycle engines to show marked difference in 
consumption; but for the same make to show such a 
vast difference would lead one to suppose that from 
defect in construction, variation in the location and size 
of ports, imperfect carburation, difference in amount of 
muffling, leaking, rings, etc., one engine was not doing 
so much work as the other, and the other was wasting 
fuel. 
M M. R., Baltimore, Md.— My engine is a double cylinder of 
16 horsepower. When I start I close the auxiliary air valve and 
then gradually open it to perfect the mixture. If I open it a 
little too much the speed increases perceptibly for a few revolu- 
tions, and then the engine slows down, begins to "back fire and 
stops. What is the cause, and how can I remedy it? 
Ans. — Your engine does just the same as all engines 
using similar method of carburation. It goes to show 
that, in order to run without stopping, the mixture must 
be a little too rich in gasolene to make up for uneven 
proportions. If your forward cylinder ignites first, the 
after one usually gets the richer mixture. In some 
cases changing the exhaust cam and ignition so that 
the after cylinder ignites first will help matters. If 
you will take notice you will find that the after cylinder 
is the one that misses explosions, rather than the for- 
ward, when mixture is bad. 
A. B. S., Troy, N. Y. — I wish to paint my engine. Aluminum 
does not seein to look well when in contact with grease. What 
would you advise using? 
Ans. — Clean the engine carefully with kerosene, then 
naphtha, and wipe dry, removing all bright parts, which 
can be polished with emery cloth and oil. With fine 
sandpaper smooth all rough parts, and give it a coat 
of good, ready-mixed gloss carriage paint. This will be 
fcund to last longer than enamel paint, and will stand 
heat and wet better. 
B. B. J., Portland, Ore. — How much power ought it to take to 
drive a 24-inch, two-bladed propeller? My engine is a double- 
cylinder, 12 horsepower, and I think cylinders are 6%in. diameter 
and stroke 5%in. 2. The propeller that came with the engine, 
24in. diameter, drove the boat 6% miles, with engine running 340. 
Next one, 22in. diameter, at 318 r. p. m. showed speed of over 7 
miles, while one I designed myself, 24in. diameter, two-bladed, 
allowed the engine to run over 400 r. p. m. and the boat did not 
make 5% miles. I am not going into the propeller wheel business, 
but would like your views on the results obtained. 
Ans. — The diameter of a propeller wheel does not 
enter so much into power computation as pitch, amount 
of blade surface, speed, regularity of the blades, one to 
another, frictional resistance in the water and sub- 
mergence. Providing your boat was not too heavy 
and of/fairly easy lines, your engine ought to drive a 
24m. diameter wheel, 30 or 32m. pitch, provided the 
blades were 8 to ioin. wide, 350 r. p. m. at a wharf trial, 
provided the wheel could be kept submerged. We 
think, however, that probably your engine diameter 
is s^in. and stroke 6 l / 2 'm., for it is not the usual custom 
among Americans to use a stroke shorter than the 
bore. Some modern English manufacturers have 
adopted the short stroke, one in particular making his 
cylinders sin. diameter, 3m. stroke. 2. In a compari- 
son of your three wheels, you should look to the en- 
gine speed as well as the speed of the boat. The 22in. 
diameter wheel was better proportioned than either of 
the others, for it took less power to drive the boat 
7 miles than to drive her 6^2, or even S T A miles at 
higher engine speed. If your engine did not have too 
much vibration at 400 r. p. m., a wheel of the same 
general design as the 22m. diameter, but with 12^ to 
15 per cent, less pitch, ought to give you even better 
than 7 miles per hour. It would seem that the two 
24m. wheels both had excessive pitch and too little 
blade surface. Pitch probably was irregular, and the 
blades not true with each other. 
Ocean-Going Motot Boats. 
Mr. W. E. H. Humphries, a Cambridge science gradu- 
ate who has devoted himself to the study of the use of 
high-power internal combustion engines for submarine 
vessels and is a practical motorist of wide experience, 
writing on motor boat building in the publication To- 
day, says that the folly of those makers who propose 
competing in the Atlantic motor boat race with 40ft. 
boats furnished with 100 horsepower motors should be 
apparent when he states that they would require for 
the journey 15 tons of fuel, which would occupy more 
than the whole cubic space of the hull. Mr. Humphries 
fears that many of the competitors in the trans-Atlantic 
race will fall into the mistake of throwing any handy 
big engine into any convenient boat without regard 
to the question of design, proper engine bed, distribu- 
tion of weight, etc. The motor boats which crossed 
the English Channel, "excellent as they were for their 
own particular purposes, were more or less freak 
boats," because in design they fell away from the lines 
normally maintained in marine practice. In yacht de- 
signing" "the highest ambition of those who aim at 
speed is to exceed a speed in knots greater than the 
square root and a quarter of the vessel's length. The 
Atlantic liners cannot do it; motor boats and the tor- 
pedo boat destroyer can, but such speed is only attain- 
able at enormous extravagance and by making the ves- 
sels mere receptacles of vibrating machinery and limit- 
ing their range." 
Writing on this subject for the Pall Mall Gazette, he 
expresses the opinion that to cross the ocean in a man- 
ner to fulfill the published details a boat must be nearer 
400ft. than 40ft. The conditions of the race are that 
the boats shall be able to travel at a speed of at least 
15 knots, shall carry all their own fuel, lubricating oil, 
and spare parts, and shall start with at least six persons 
on board. This at once rules out of the contest all 
small racing craft, for, apart from questions of accom- 
modation and seaworthiness, they could not carry the 
fuel to feed their engines. The normal consumption 
of a petrol engine may be regarded as one pint per 
horsepower per hour, which means that for every 100 
horsepower of the engine there is consumed approxi- 
mately 300 gallons per day. With a 15 knot boat the 
passage from Havre to New York might be expected 
to occupy from twelve to fifteen days. Hence for every 
100 horsepower of the engine it will be necessary to 
carry 4,500 gallons of fuel, occupying approximately 
723 cubic feet of space and weighing 15 tons, or more, 
if fuels heavier and less efficient_ than petrol be em- 
ployed. To complete the absurdity, the Calais-Dover 
racer would require, to enable it to cross the Atlantic, 
a bulk of petrol of greater weight and greater displace- 
ment than the boat itself. Seemingly nothing smaller 
than a torpedo boat destroyer could attempt to fulfill 
the conditions laid down, and for a vessel of these di- 
mensions an engine of 500 horsepower would not be 
excessive. Marshall HalsteaPj Consul, 
Birmingham, Eng., Oct. 
Design [iot an [Open Launch. 
We are publishing this week, through the courtesy of 
Messrs. Small Bros., the designers, the complete plans of 
an open cruising launch. The boat was designed for Mr. 
H. W. Hornthal, of Norfolk, Va. As a comfortable, 
roomy boat for general day use, she has given the greatest 
satisfaction to her owner. She develops a speed of about 
12 miles under favorable conditions. 
The dimensions are as follows : 
Length — 
On deck 31ft. 9 i n , 
Greatest 34ft 
L.W.L '..32ft. 6in. 
Overhang — 
Forward gin. 
Aft gin. 
Breadth- 
Extreme .- 7ft 
L.W.L ;;* 6ft iin. 
Draft- 
To rabbet IIt . 8in. 
Extreme 2 ft. 4m. 
h reeboard — 
Forward 3 ft. gin. 
Least 2 ft. iin. 
Aft 2ft. 4in. 
_ The forward cockpit is 8ft. long and the after cockpit 
is Qft. long. Between the two there is a deck space of 
3ft. 9m., giving great transverse strength. Under this 
deck space the engine is placed well out of the way, yet 
can be easily reached. 
The Societe Nautique of Geneva. 
BY JOHN F. REVII.LIOD, VICE-PRESIDENT. 
The Societe Nautique, of Geneva, Switzerland, was 
established in 1872. It is the only vacht club in that 
place, and since it was organized its growth has been 
steady. To-day it has many members and quite a num- 
ber of native-built boats enrolled. The club has always 
been managed in the ablest and most conservative way 
by the various gentlemen who have held office from the 
time of Dr. Vincent, the first president. 
Aside from the natural beauties of the Lake of Geneva, 
which are incomparable, the lake is of such a shape that 
a regatta may be witnessed from any point along the 
shore. 
It has now 350 members, at the head of which everv 
year a committee of eleven members is elected. The 
members of the committee for 1904 are : President, E. de 
Royer; Vice-Presidents, Felix Warmer, John F. Revil- 
hod; Secretaries, Philip Serex, Jean Mirabaud; Treas- 
urers, Armand Martin, Henri Orange; Trustees, Eugene 
Corte, Charles Serex, Frederic Seylaz ; Training Chief, 
Oscar Hunziker. The committee looks after the organ- 
ization of the regattas of the year and fixes the dates 
thereof; it publishes a report of the regattas of the past 
year. It sometimes happens that members of the club 
go to the Mediterranean during the winter season and 
take part in the various regattas. The chib has members 
that are exceedingly keen on yachting. AI. Godinel, the 
naval engineer, is a member, and many of the boats sail- 
ing on the lake were built from his designs. He was of 
assistance in getting the new formula for meas- 
uring and classifying sailing yachts. The society has 
on one of the prettiest quays of the town of Geneva a 
club house, which is more comfortable than luxurious, 
and is built in the shape of a U; in the center part is a 
club room and reading room ; and in the two wings the 
•rowing boats are stowed away. A jetty on the north 
side enables the sailing boats and launches to be safely 
anchored. 
A good many of our members live on the shores of the 
lake m charming country places, and on regatta davs 
111 the morning one can see the coast full of white dots— 
the sails of their boats being put in shape for the regatta. 
The race committee can almost tell beforehand how 
many boats will take part in the regatta of the afternoon. 
_ In the Societe Nautique of Geneva boats are divided 
into three sections— sailing, rowing, and motor launches. 
The sailing yachts are divided into eight classes: Fifth 
class for yachts over 5 tons ; fourth class for yachts fron 
3 to S tons ; third class for yachts from 2 to 3 tons ; seconc 
class for yachts from 1 to 2 tons; first class for yacht 
up to 1 ton ; one-design class, Y4 ton. Series A for smal 
boats with 20 square meters of canvas; series B for smal 
boats with 15 square meters of canvas, measured accord- 
ing to the following formula : 
T= ( L ~f) xfxVs 
L=Length. - r 
P=Perimeter in meters. 
S— Sail area in meters. 
The sailing section came into existence in 1903. ; 
was founded by several members owning sailing yacht 
and besides the general subscription to the society thf 
pay an annual fee of $50, the whole amount of which > 
given in prizes. The members of this section have r- 
gattas of their own besides those of the society. The* 
are about fourteen regattas during the season, and thf 
are sailed on Sunday. The society gives generally oe 
medal for three yachts racing together in one class, tw 
medals for four, and three medals for seven yachts.' B 
sides these medals the sailing section usually gives one • 
two prizes, either silver plate or something else. 
The regattas take place on Sunday. The course ; 
generally laid off in triangular shape; if the wind ; 
strong enough the course is sailed twice over. There a> 
gome challenge cups, and the late Dr, W- Mareet ga- 
