less so, as it sometimes extends
a little into the neighborhood; but the yellow fever rigorously so,
confined within narrow and well defined limits, and not communicable
out of those limits. Such a constitution of atmosphere being requisite
to originate this disease as is generated only in low, close, and
ill-cleansed parts of a town, I have supposed it practicable to prevent
its generation by building our cities on a more open plan. Take, for
instance, the chequer-board for a plan. Let the black squares only be
building squares, and the white ones be left open, in turf and trees.
Every square of houses will be surrounded by four open squares, and
every house will front an open square. The atmosphere of such a town
would be like that of the country, insusceptible of the miasmata which
produce yellow fever. I have accordingly proposed that the enlargements
of the city of New Orleans, which must immediately take place, shall be
on this plan. But it is only in case of enlargements to be made, or of
cities to be built, that his means of prevention can be employed.

The _genus irritabile vatum_ could not let the author of the Ruins
publish a new work, without seeking in it the means of discrediting that
puzzling composition. Some one of those holy calumniators has selected
from your new work every scrap of a sentence, which, detached from its
context, could displease an American reader. A cento has been made of
these, which has run through a particular description of newspapers, and
excited a disapprobation even in friendly minds, which nothing but the
reading of the book will cure. But time and truth will at length correct
error.

Our countrymen are so much occupied in the busy scenes of life, that
they have little time to write or invent. A good invention here,
therefore, is such a rarity as it is lawful to offer to the acceptance
of a friend. A Mr. Hawkins of Frankford, near Philadelphia, has invented
a machine, which he calls a polygraph, and which carries two, three, or
four pens. That of two pens, with which I am now writing, is best;
and is so perfect that I have laid aside the copying-press, for a
twelvemonth past, and write always with the polygraph. I have directed
one to be made, of which I ask your acceptance. By what conveyance I
shall send it while Havre is blockaded, I do not yet know. I think you
will be pleased with it, and will use it habitually as I do; because it
requires only that degree of mechanical a