An attempt to arrive at an explanation of the various mechanisms of fluid friction. Its Tart I an expression for the velocity distribution in the boundary layer which has hitherto been obtained only empirically is derived from a consideration of “eddy-viscosity”. The exponent of the distance from a solid flat wall in the above expression is in this case 1/8 instead of 1/7 which is usually found experimentally. The effect of the surface roughness on the mode of velocity distribution is also dealt with in this part.
Part II deals with the problem of the frictional resistance of the flat wall. The formulae of both pipe friction and of the frictional resistance of the flat plate can be obtained by assuming an appropriate value to each of the two constants. The process is not unlike that of Kármán who has for the first time found the numerical relations of the constants of the above two formulae, but in the present case the physical nature of these constant have been made clear. Here also the effect of the surface.roughness is considered. The laws of similitude of motion of a very rough and an imperfectly smooth surface are of interest.
In the last part are the applications of the preceeding mode of treatment to the care of the curved wall. The sudden fall of the resistance coefficient of the cylinder at a critical condition finds its explanation. for the first time, and the profile resistance of the aerofoil and the frictional resistance of he airship envelope have been calculated in this tart. Appendices deal with some allied problems which seemed to be interesting.

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Comparison between the actual boiler data of the recent Japanese and Foreign coal fired steamers, giving useful hints to designers to secure a good combustion, and also recommending the adoption of the double ended boilers on large ships.
From the various results of combustion tests, to get an efficient burning, it is necessary to increase the draught by the large area of funnel, and the funnel damper to be fitted each boiler for independent control and the divisions in funnel to be extended to the top.
Calling the special attentions necessary for the orient and pacific coast services, and also for the superheater headers, and efficient feed water filters.
Concluding with an argument for the necessary improvements to be always made upon the Scotch boiler until superseded by the super-high pressure boiler.

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1. The comparison between the steam engines and diesel engines.
Fuel, coal and liquid, and their management. Reciplocators and turbines.
2. The view on the management.
The various valves of two and four cycle engines, and troubles for their management and maintenance.
The troubles arising from piston rings, piston cooling systems, and deterioration of lubricating oil.
The fuel injection methods. The gauge system.
3. The view on the running.
The length of time for adjusting in the actual service.
The scarcity of working hands.
The starting time and starting air. The governors.
The cleaning of piston rings &c.
The electric motor aux. machinery.
The ventilation, noise and vibration.
The hot water for bathing.
The individual opinions of the crew (with table).
The amount of wearing out of moving parts (with table).
4. From the economical point of view.
The cost of building. The weight.
The expense of repair (with table).
The fuel expense (with table).
The lubricating oil consumption (with tables).
The manning expense (with table) &c.

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The anther first describes the failure of the circumferential claw bolts which occured one after another during the voyage and the procedures he took as the first engineer of the S. S. “Hakozaki maru”. Next he explains the material tests of the bolts and the investigations of the failure which were done by Mitsubishi Zosen kaisha Ltd.
Finally, he adds his own opinions about the failure of the bolts from the standpoint of a sea-going engineer.

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When a turbine steamer pitches or yaws, such a motion being that of precession with respect to the turbine discs, they are subjected to a gyroscopic force perpendicular to their plane. As this force is evidently distributed harmonically around the discs, and is fixed with respect to axes of reference fixed in the ship, the revolving discs are set to a transversal vibration having one nodal diameter, which is fixed with respect to the said axes of reference.
The author began with the solution of the equation of such vibrating motion without taking the effect of centrifugal stresses into consideration. Next, it was shown how a correction for the effect of the centrifugal stresses may be introduced.
The result obtained by the theoretical investigation was confirmed by a model experiment.
This phenomenon has so far escaped the notice of turbine engineers, but the author emphasizes the necessity of a keen attention for it.

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The apparatus is to quickly haul the vessel bodily above water in order to rescue the crew in sunken submarines. Every submarine is attached with a special fitting with a projection which a leading wire and a bouy are joined to. The wire and the bouy have connection to a telephone bouy. If the vessel founders and the telephone bouy lifts, the above mentioned bouy and wire can be picked up. From one side of a salvage vessel another fitting with a tenon is led downward along the wire and clutched to the above mentioned fitting on the submarine. A tackle is joined to this fitting and the fall is led over the salvage vessel to another submarine hunged on the opposite side of the former.
A suitable number of such apparatuses are provided on the wrecked submarine, the salvage vessel, and the hunged submarine. On the completion of all apparatuses, the hunged submarine is sunk down by flooding its inside. The weight of the hunged submarine and some pull given by winches are available in hauling the wrecked submarine upon water surface. Afterwards the sunken hunged submarine is again lifted above water by applying pneumatic air.

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About 40 test pieces were prepared for this purpose. These test pieces consisted of various kinds, i.e., some with one opening in single plate, some made thicker on both sides of the opening, some with coaming to the opening and side coamings corresponding to shell plate of ship, some having two openings consecutively, some with rounded corners, and others with straight coner doublings or with doublings round the corners etc. These test pieces were pulled by a testing machine along the centre line or with some inclination to the centre line, or obliquely shifting the grips of the mochine to a different plane, or combined. The results were recorded with regard to the elastic limit, the maximum and after broken. The fracture occured in some at corners and in the others between corners, and no distinct relation was to be found between the points of fracture and the direction of pull, but the lines of fracture appeared withoute xception at right angle to the longer edge of the test piece. When the fracture occured at corner, it was at the end of the round or the doubling, with one exception which occurred across the doubling (that doubling being very thin, i.e., one-quarter of deck plate). With respect to the deformation of the opening, the breadth was not changed or changed very slightly within the elastic limit, but the length became visibly longer. The strength of the test piece per square inch section became approximately 3% greater than that of the standard test piece of the same plate.

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