March 14, 1896. j 
JOSEPHINE Designed and Built by Lewis Nixon for P. A. B. Widener, 1896. 
and refrigerating machinery, a fresh-water distilling plant— making 
the vessel independent of shore supplies of fresh water, a great desid- 
eratum in many fever-ridden ports— steam and hand steering gear, 
steam windlass and two power launches. She will have a two-masted 
schooner rig. No cumbersome bits obtstruct the gangways, but in- 
stead a neat, combined chock and cleat is used, which is entirely out 
of the way. She has a steel bowsprit: The yacht has a long overhang 
at each end and very flaring lines forward, tending to keep her beam 
up in a seaway. 
The large square stern gives the owner a grand open air lounging 
room. Double awnings will be used, with a 4in. air space between. 
Electric lights will be used throughout, and a storage battery will run 
the lights after midnight so that the tremor of the dyoamo will not 
annoy those who wish to sleep. An arc of lights stretching over the 
masthead will be supplied, and a Bearch light will be carried on the 
forward end of the house. 
The engines are triple expansion, 18, 27 and 42in. in diameter by 28in. 
stroke. Steam is supplied by two boilers with 120sq. ft. of grate sur- 
face and 3,600ft. of heating surface. These boilers are fitted with 
powerful blowers so that the vessel can run at a high rate of speed if 
desired. She will be able to make 6,000 miles without recoaling. 
A Model Tank for the Navy Department. 
Thk following bill has been introduced in Congress by Representative 
Hilborn,'of California, to fill a^want tbatjhasjlong been felt by the naval 
constructors of the United States. The cost of the plant is but small 
in comparison with the value of the results to be obtained, on which 
■may largely depend the wise or unwise expenditure of millions of dol- 
lars in the construction of new warships. The immediate importance 
•of an adequate plant for experimental work and investigation is so 
little understood and appreciated that it is quite possible that the bill 
may not pass, but we earnestly hope that it may. Apart from its use 
by the Navy Department, the tank will practically be at the service 
■of private shipbuilders as well. When even private firms abroad con - 
aider such an experimental plant, expensive as it is, as a necessary 
and profitable part of their equipment, the Government of the United 
•States should be capable both of appreciating and paying for one. 
A bill providing for a model tank for the U. S. Navy: 
Be it enacted by the Senate and House of Representatives of the 
United States of America in Congress assembled, that the Secretary 
of the Navy be, and he is hereby, directed to establish a model tank 
with all proper appliances for the purpose of investigating and de- 
termining the most suitable and desirable shapes and forms to be 
adopted for U. S. naval vessels. 
Sec. 2. This model tank shall be located at Washington, D. C, upon 
such government reservation already under the control of the Navy 
Department as the Secretary of the Navy may designate, and shall be 
built upon plans approved by him. A naval constructor shall, under 
the direction of the Bureau of Construction and Repair of the Navy 
Department, have charge of the model tank and all work done in con- 
nection with it. 
Sec. 3. At this model tank experiments may be made for private 
shipbuilders upon the authorization of the Secretary of the Navy; 
provided that the cost of material and of labor of per diem employees in 
making such experiments shall be defrayed by the private shipbuilder; 
and provided further, that the results of such experiments shall be 
regarded as confidential and shall not be divulged without the con- 
sent of the shipbuilder for whom they may be made. 
Sec. 4 For the model tank with all necessary buildings and appli- 
ances $100,000 are hereby appropriated. 
Model Experiments in Ship Resistance. 
We reproduce from Engineering the following account of a paper 
read at the meeting of the Institution of Mechanical Engineers 
(British): 
On the members assembling on Friday evening, Jan. 31, the presi- 
dent, Mr. E. Windsor Richards, occupied the chair. The first paper 
taken was by Lieut.-Col. Thomas English, and was on "The calcula- 
tion of Horse-Power for Marine Propulsion." The object of the paper 
was to describe a method of calculating, from the results of a single 
sea trial of one ship, the horse-power necessary to propel another 
ship, of the same type, at any given speed. By the method treated 
upon, it is practicable with the ordinary appliances of a shipyard to 
approximate closely results which could otherwise only be obtained 
with a model tank. The author referred to Froude's method of 
separating the skin friction resistance from the wave-making resist- 
ance. The former could be readily tabulated, while to ascertain the 
latter experiments have to be made either with an actual ship or with 
a corresponding model in a tank. The apparatus described consists 
of a small electric motor, furnished with a resistance coil, and running 
at a speed of about 1,000 revolutions per minute. The motor gives off 
about one-sixth of a brake horse-power, or a pull of about 8.41b3. 
through 631ft. par minute on on endless piano wire stretched over two 
pulleys about 350ft. apart, one pulley being driven by the motor. The 
wire, therefore, is suspended horizontally over the surface of any con- 
venient sheet of water. A towiag framjis usad, consisting of two 
similar and parallel levers, each 60in. between centers, and pivoted at 
their ends to the decks of the models. In this way the models are 
kept parallel to each other. The levers are divided, and are attached 
by short collars which can be clamped at any required graduation to 
pivots at the end of a bar, which is of the same length as the distance 
between the pivots on the deck of e ch model, that distance being 4tt. 
This bar carries a vertical spindle, to which the lower wire is con- 
nected by a ring which can travel up and down the spindle and thus 
allow for the sag of the wire. 
Vertical slotted guides embrace the wire at both ends of the bar, 
and thus keep the latter, and therefore also the models, in a steady 
course. Loose diagonal guides connecting the models serve as stops 
to prevent them from coming close together when one lags behind the 
other. The levers are always clamped at the same graduation on 
each, and this graduation is varied by trial until the models tow 
abreast at the requirel speed. It is found that the requisite speed 
can readily be obtained within limits of 0.02 knots per hour. The 
principle upon which results are obtained is based upon the proposi- 
tion that it will always be possible to make two models of such scales 
that the same absolute speed will for one of the models correspond 
with that of a ship which has been tried at sea; aid for the other 
model with that desired for the proposed ship. The actual resistance 
of the model of the ship already tried can be calculated, and if the 
ratio of the total resistance of the two models at the same speed i 
found by trial, the actual resistance of the second model will bj 
known; therefore the resistance of the proposed ship at the desires 
speed can be calculated. The models, which are 10ft. long, are made 
of yellow pine. 
The discussion was opened by the reading of a letter from Mr. 
Froude, who was unable to be present. The method proposed was 
ingenious, Mr. Froude said, for obtaining horse-power estimates with- 
out laboratory apparatus. The advantage of the system rested in the 
fact that the two elements which are most difficult to estimate were 
approximately common to both models. As a matter of detail, Mr. 
Froude would suggest that when towing the models of 10ft. long 
alongside each other, with a distance of nearly 4ft. between them, 
their respective waves might interfere with the result. 
Prof. Barr said that if the resistances were not exactly equal while 
the models were being towed, instability might result, and the models 
would come together. He had designed an apparatus involving simi- 
lar principles, but this was intended for measuring wind resistances. 
He also had thought that the point mads by Mr. Froude might arise in 
regard to the models interfering with each other. He would ask if 
there was any advantage in cost of production in using wood models 
over those made of wax, which were generally employed in tank ex- 
periments. 
Mr. Leslie Robinson referred to the examples given by the author in 
the paper, in which he determined the horse-power required for a 
torpedo-boat destroyer of 300 tons displacement and 30 knots speed. 
The Janus and Lightning, built by Palmer's Company at Jarrow, had 
displacements of 247 tons, and they steamed on trial at 27.85 knots. 
The wetted surface of the Janus was 3,796sq. ft.; on the proposed ves- 
sel it would be 4,321sq. ft. The indicated horse-power of the Janus at 
27.8 knots was 3.840; while the Lightning, steaming at 27.9 knots, re- 
quired 3,990 indicated horse-power. Working these figures out, the es- 
timated horse-power required for the 30 knot vessel would be 5,220 H. 
P. Referring to these figures, Mr. Robinson asked whether the 
details of the calculations set forth had been obtained by means of 
actual experiments from models. He asked this because the horse- 
power to give the speed seemed low; those accustomed to designing 
vessels of this class would give rather 6,000 indicated horse-power, 
Col. English, in replying to the discussion, said he would commuri 
TRENT MIDSHIP SECTION. 
