328 On the Curvilinear Form 
them stronger in those parts by a different disposition or com- 
bination of materials, until the year 1811, when Sir Robert Sep- 
pings introduced a method of strengthening the bow, and afford- 
ing protection to the mariners, by carrying up the timbers so as 
to form around bow; and subsequently in June, 1816, he pro- 
posed that the same system should be adopted in the stern, a 
part that still more required to be strengthened, so as to form 
the circular stern which is the subject of the present essay, 
The advantages derived from the circular sterns may be 
classed under the following heads : 
Ist. A considerable addition to the strength of the ships. 
2nd. Safety to the people employed in them, both from the 
effects of a sea striking their sterns, and from shot fired by the 
enemy. Soar 
3rd. The additional means afforded for attack or defence. 
4th. The improvement inthe sailing qualities of the ships by 
the removal of the quarter galleries. 
The insufficiency in point of strength of the old method of 
constructing the sterns, is proved in Sir Robert Seppings’s letter, 
by his giving, from official reports, cighty-nine instances in ships 
of the line, and eighty in frigates, of the great weakness of that 
part of the ships; many of these were commanded by officers 
who are celebrated for activity and prowess during the two last 
wars. This defect being so general, led to the consideration of 
the best mode of remedying it ; and the acknowledged strength 
of the round bow, a part subjected to the action of far greater 
forces and strains than the stern, naturally led to the considera- 
tion of fortifying the latter by the same mode of timbering, and 
from this arose the circular stern. Before the introduction of 
this system, the new mode of ship building might truly be said 
to be incomplete, for the shelf-pieces and waterways, as well as 
all the planking above the wing transom, which may be called 
internal and external hoops, were cut off, and hence left the 
stern the only weak part in the ship; for itis an axiom in me- 
chanics that the strength of any fabric may be measured by the 
weakest part, subjected to the like strains or action. Itis, then, 
the mode of timbering these sterns, and a continuity of the in- 
