164 = Mr. Town’s new mode of Bridge-building. 
which the mode itself does not command, even on the most 
strict philosophical investigation as to its mathematical prin- 
ciples, the easy, practicable, and advantageous application 
of materials, the advantages it possesses in mechanical ex- 
ecution, and its simplicity, strength, economy, and durabili- 
ty, as a general and uniform mode of Bridge-building. 
Science and practice will, in a short time, decide on this 
question so important to this extensive country. , 
I shall conclude this article by a few ideas, taken from 
the celebrated Robert Fulton’s treatise on canal navigation, 
page 117, and subsequent pages. ee 
d to where timber is 
scarce and consequently expensive. But in such countries 
fair criterion to judge of their application by calculating on 
the expense of a bridge of stone, and one of wood, and 
bridges in America of an extensive span or arch, in order to 
suffer the ice and collected waters. to pass without inte 
