+----------+----------+----------+---------+
| 8-INCH. | 100-PDR. | 60-PDR. | 30-PDR. | 20-PDR. |
-----------------+----------+----------+----------+----------+---------+
| lbs. oz. | lbs. oz. | lbs. oz. | lbs. oz. | lb. oz. |
Long | -- | -- | 3.4 | 1.8 | 1. |
Short | -- | 3.11 | 2.2 | -- | -- |
-----------------+----------+----------+----------+----------+---------+

386. SHELL AND SHOT GAUGES.

---------------------------+----------+----------+----------+----------+
| 100-PDR. | 60-PDR. | 80-PDR. | 20-PDR. |
---------------------------+----------+----------+----------+----------+
Greatest | 6.36 | 5.27 | 4.17 | 3.64 |
True diameter | 6.35 | 5.26 | 4.15 | 3.63 |
Least | 6.33 | 5.24 | 4.14 | 3.61 |
---------------------------+----------+----------+----------+----------+

387. In the rifle-guns of Mr. Parrott, provisionally adopted, it is
intended to retain the full charge of powder which a smooth-bore gun
of the same calibre would have with a round shot. The projectile for
the rifled gun is to be usually ten times the weight of this
charge.[41]

388. To obtain greater initial velocity, projectiles of less than the
full weight have been provided--solid shot of 70 pounds for the
100-pounder, with the front end "chilled." Such projectiles, though
not suited for long ranges, will be effective at 1,000 yards or less,
and are well calculated to act against oblique surfaces of iron.

389. The powder for the 100-pounder and 60-pounder should be of Rifle
(or, as formerly called, No. 7):--for the smaller calibres, 30-pounder
and 20-pounder, of Navy cannon powder. The cartridge-bags are the same
as those prescribed for similar calibres of smooth-bore guns.

390. The Parrott guns have been arranged for the use of a certain kind
of projectile, supplied by the inventor. These have reference not only
to the calibre and mode of rifling, but to the design of the gun
itself. For these reasons, the inventor objects to the use of any
other than his own form of projectile in the guns of his invention.
This request has been acceded to in the heavier calibres. The shells
of Schenkl and Hotchkiss have also been used, however, in the smaller
calibres.

It is not considered expedient to describe thes