ibs having been
predetermined by suitable calculation.

The above described methods while not claimed herein are to form the
subject-matter of a separate application.

Having described my invention what I claim is:

1. A projectile provided with a chamber extending along its length, the
walls of said chamber being provided with longitudinal ribs extending
in a spiral direction from the base of the chamber to the forward end
thereof.

2. A projectile provided with a chamber extending along its length, the
forward end of said chamber being pointed, the walls of said chamber
being provided with longitudinal ribs extending in a spiral direction
from the base of the chamber to the point thereof.

3. A projectile having the fibers of its material twisted in a spiral
direction from the base of said projectile to the end thereof.

4. A projectile having the fibers of its material twisted in a spiral
direction from the base of said projectile to the end thereof, said
projectile having a central chamber, the walls of which are provided
with longitudinal ribs extending in a spiral direction from the base of
the chamber to the point thereof.

In testimony whereof, I have signed my name to this specification in
the presence of two subscribing witnesses, this sixth day of December,
1906.

CARLOS DE ZAFRA.

Witnesses:

EMILO BELARI,
EMMA RODERICK.

Bibliography

ORDNANCE AND GUNNERY BRUFF

TEST BOOK OF ORDNANCE AND GUNNERY INGERSOLL

REPORT ON THE ART OF WAR IN EUROPE--1854-1855-1856
COL. R. DELAFIELD, U.S.A.

JOURNAL OF THE U.S. ARTILLERY

THE SCIENTIFIC AMERICAN

SPECIFICATIONS OF THE BUREAU OF ORDNANCE, U.S. NAVY DEPARTMENT

SPECIFICATIONS OF THE ORDNANCE DEPARTMENT, U.S. ARMY

[Illustration: The de Zafra Improved Armor-Piercing Shell]

End of the Project Gutenberg EBook of The Development of Armor-piercing
Shells, by Carlos de Zafra

*** END OF THIS PROJECT GUTENBERG EBOOK DEVELOPMENT OF ARMOR-PIERCING SHELLS ***

***** This file should be named 33535.txt or 33535.zip *****
This and all associated files of various formats will be found in:
http://www.gutenberg.org/3/3/5/3/33535/

Produced by The Online Distributed Proofreading Team at
http://www.pgdp.net

Updated editions will replace the previous one--the old editions
will be renamed.

Creating the works from pub