: 
TRANSACTIONS OF SECTION G. 949 
These new alloys would enable us to provide rapidly in any emergency the 
artillery and armament necessary for the public service. 
3. Some new Telemeters or Range Finders. By Professors A. Barr and 
W. Srroup. —See Reports, p. 499. 
FRIDAY, SEPTEMBER 6. 
The following Reports and Papers were read :— 
1. Report of the Estuaries Committee.—See Reports, p. 512. 
2. Report of the Graphic Methods Committee. 
3. The Process of Manufacturing Netting by slitting and expanded 
Sheet Metal. By J. F. Goupine. 
Expanded metal is an article so dissimilar to other manufactures of metals as to 
require an arbitrary name, and the one given it is but meagrely suggestive of the 
process inyolved in its production, and not of its qualities or appearance, as these 
are only understood by the fullest description, or by ocular or physical demonstra- 
tions and tests; but the name, suggesting the expansion of metal, does serve to 
excite attention to the fact that thereby some new product of metals has been 
made. 
Briefly stated, the process of making expanded metal is the employment of a 
machine, which so operates on a sheet or strip of metal as to slash it at intervals 
in parallel lines, so as to leave uncut spaces, which serve to maintain the connec- 
tion between all the strands produced by the act of slashing. The method by 
which this slashing, as well as the opening up of the sheet or strip into meshes, is 
performed is peculiar, and one which makes it possible to transform the sheet or 
strip of metal into a finished article at one operation, and to this achievement is 
due the great commercial value of the invention. The simultaneous act of slashing 
and opening or expanding the sheet or strip at the slashes, leaving uncut spaces, 
and giving uniform design and set to the metal forming the meshes, is exceedingly 
novel, and most difficult of explanation, except by witnessing the movements of 
the machines. 
These machines are necessarily heavy to secure rigidity and consequent accuracy 
in the slashing and shearing of the metal, but they are at once recognised to be 
very compact and simple. 
Any homogeneous metal, such as steel, copper, brass, &c., can be employed. 
The machines as now constructed automatically feed a strip of steel between 
their cutters, which, as explained, simultaneously slash and expand the metal into 
meshes. These strips may be of any width, from 1 to 8 inches or wider, according 
to the design of the machine or width of expanded metal desired ; the ratio of ex- 
pansion being determined by the size of the mesh. Thus, a strip of steel 7 inches 
wide by 9 feet long, made into $-inch mesh for lathing, gives as a result a sheet of 
finished product, 18 inches wide and about 5 per cent. shorter than the original 
strip, whereas a strip of metal 6 inches wide and 9 feet long, made into a 4-inch 
mesh for fencing, gives as a result a finished sheet 4 feet wide by 8 feet long. 
The cut edges of the strands forming the meshes are presented to the surface in 
the finished sheet, thus giving rigidity to the expanded sheet many times greater 
than the original flat sheet or strip. 
