THE ROYAL ARTILLERY INSTITUTION. 
395 
REPOET 
OB' 
EXPERIMENTS INSTITUTED BY THE ASSISTANT SUPERINTENDENT OF 
THE ROYAL CARRIAGE DEPARTMENT, AT THE SUGGESTION OF THE 
ROYAL ENGINEER COMMITTEE, AND SANCTIONED BY THE DIRECTOR OF 
ORDNANCE, 29th: AUGUST, 1863, TO ASCERTAIN THE ACTUAL VERTICAL 
PRESSURE EXERTED BY THE VARIOUS NATURES OF FIELD AND SIEGE 
ARTILLERY, WHEN PASSING OVER PONTOON BRIDGES ; AND ALSO 
WHETHER THE MAXIMUM PRESSURE IS OCCASIONED BY THE HORSES 
OR CARRIAGE. 
By Lt.-Col. G. SHAW, R.A. 
ASSISTANT SUPERINTENDENT, EOYAL CARRIAGE DEPARTMENT. 
One of the weigh bridges in the Royal Arsenal having been selected, as 
affording the best means for carrying out these experiments, and it having 
been, found that the weights of moving bodies could not be accurately 
ascertained without some method of self-registration the following contrivance 
was devised for the purpose :— 
An iron spindle was dropped through a fixed bracket (vide Diagram), so 
NN 
[VOL. III.] 
