AERONAUTICS IN RELATION TO NAVAL ARCHITECTURE. 49 
In assembly all butts are covered with glue. All woodwork is given two coats of 
shellac as soon as it is in place, and is finally given two coats of varnish to prevent 
the absorption of moisture. 
All boundaries of the bottom are sheathed with brass strips set in marine glue. 
This affords protection and insures water tightness. The float attachments are lo- 
cally reinforced and strengthened to transmit the loads to the important members. 
The method of construction involves the use of a wooden form shaped to the 
molded lines and cut into sections to allow of removal. 
The center-line girder is next assembled with the bow and stern blocks and the 
step. This is then assembled with the form in which the slots for the ribs and the 
bilge stringers have already been cut. The frames and stringers are then bent and 
set and faired flush with the surface of the form. Next the inner ply of planking, 
which has already been shellacked and varnished on the inner face, is applied and 
secured to the frames and longitudinals by means of screws. Steaming is unneces- 
sary. In some cases it is necessary to humor the sharp curvature at the ends by the 
use of hot water applied with a swab. 
This first ply of planking is then coated with marine glue and the sheeting 
is applied, followed by the second ply of planking, which is treated with marine glue 
as fast as each piece is shaped. The second ply is secured in a manner similar to 
the first ply. The seams of the first ply are traced on to the second ply in pencil, for 
the purpose of laying out the nails securing the two plys together. Once the sec- 
ond ply is laid, these nails are driven at intervals of about 2 inches along the mar- 
gins of both plys of planking, the ends of the nails projecting into the wooden form. 
The form is now removed, the nails are clinched, and additional quilting nails are 
systematically driven and clinched. In the meantime the bulkheads and bottom 
planking have been assembled roughly to dimensions on a flat slab. The bulk- 
heads are now neatly fitted and inserted and secured to the frames by screws and 
glue. Next, the intermediate longitudinals are placed and secured and all special 
_ bracing and fittings for the float attachments are placed and the bottom frames of 
the bulkheads secured. The bottom planking is now carefully fitted and the drain 
plugs installed in the proper locations. The hand holes and the holes for the venti- 
lating tubes are laid off, cut, and reinforced, and then the bottom planking is ap- 
plied and secured. The ventilating tubes are next secured. The entire float is now 
turned over to the painters, who carefully sandpaper the surfaces and apply two 
coats of shellac and two coats of varnish. After this is done the step casting, edge 
strips, false keels, mud guards, and deck fittings are applied. 
Each of these floats, designed for 1,000 pounds displacement and 60 per cent 
reserve buoyancy, weighs, complete, 125 pounds. The principal dimensions are:— 
Length, 15 feet; maximum beam, 24 inches; maximum draught, 14 inches. 
The floats illustrated have been used in service with very satisfactory results. 
The aerodynamic properties of these floats are good. They have the least resistance 
when the deck is inclined at —3 degrees to the wind, and in this position have no lift; 
consequently, they present a minimum disturbance in the equilibrium of the aero- 
plane. ; 
