THE EOYAL AllTILLEEY INSTITUTION. 
87 
RECENT IMPROVEMENTS 
IN THE 
MANUFACTURE OF PEBBLE-POWDER, 
BY 
MAJOR J. P. MORGAN, R.A., 
ASSISTANT SUPERINTENDENT EOYAL GUNPOWDER EACTOKY, WALTHAM ABBEY. 
(Reprinted from the “ Journal R.U.S. InstitutionNo. 77, Vol. XVIII., bp permission of the 
Council , who also Tcindly granted the use of the wood bloclcs used to illustrate the paper). 
The points to be attained, as is well known, in any improvements in the 
manufacture of powders, are an increased velocity of projectile, a diminished 
strain on the gun, and greater uniformity of results. It was the introduction 
of heavy and rifled guns that drew attention to the importance of these, points, 
and we accordingly find that as the size and precision of fire of guns have 
increased, the necessity-for improved gunpowder has been felt in all countries. 
In a paper published in 1871,* the author entered very fully into the methods 
which have been used for determining the explosive force of gunpowder, 
showing that it is to Captain Rodman, of the United States* army, that we 
are indebted for having first taught us how the pressure of gunpowder may 
be measured in the bore of- the gun in which it is fired, This is the only 
satisfactory way of solving the question, and we accordingly find that his 
experiments led to the discovery that the means of moderating the rate of 
combustion of gunpowder lay not only in increasing the size of the grain, but 
also in increasing the density. Thus originated the American mammoth and 
perforated cake powders, which have since found their way in modified 
forms into all countries where the art of powder-making has advanced. The 
prismatic powder, which has been adopted in Russia and Prussia, is derived 
from the American perforated cake, and the mammoth powder has appeared in 
Belgium as (C poudrea gros grain” and is slowly making its way into Prance, 
Italy, and other continental countries. It has been imported into England 
under the name of “ pebble-powder.” 
As early as 1858, a Special Committee on gunpowder was appointed under 
the presidency of Colonel Ask with, then Superintendent of the Royal Gun¬ 
powder Factory, Waltham Abbey, and their investigations resulted first in 
the introduction of R.L G., and afterwards in the recommendation of "pellet- 
powder” for heavy guns. In their final Report in 1866 they recommended 
* On “The Determination of the Explosive Force of Gunpowder.” See “Proceedings E./L 
Institution,” Vol. VII., p. 413 et seq. 
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