General H.L. Abbott delivered a lecture before the Academy of Sciences in
New York, on the evening of March 21, a summary of which is given by the
_Herald_ as follows:

According to General Abbott, the country needs for its coast defenses:

Heavy guns;
Armor-clad casemates;
Disappearing gun carriages in earthworks;
Heavy mortars;
Submarine mines or fixed torpedoes; and
Fish torpedoes.

The lecturer said that this nation may be attacked in four ways: First, by
fleet and army combined, as in our revolutionary war; second, by blockading
the entrances to all our ports; third, by bombardment of our seaport cities
from a long distance; fourth, by a fleet forcing its way into our harbors,
and making a direct attack or levying tribute on our people.

The first is not now greatly to be feared. We are too distant from great
powers, and too strong on land.

The second should be met by the navy, and is, therefore, outside a
discussion of coast defenses.

The third is not probable, though it may be possible. The extreme range of
10 miles for heavy guns cannot be obtained from shipboard, and as an
elevation of only 15° or 16° can be given, not over 5 to 6 miles range is