Agriculture Reference
In-Depth Information
providing a 360
o
cutting edge. This was a development of the small bow with
a single wire used for cutting away surplus clay off the top of the box by some
brickmakers during moulding. Historically wire could be made by two meth-
ods (Trew, 2006, 1-7). From ancient times till 400 AD the 'slit and hammer'
method, cutting narrow strips from thin sheet metal was employed. Towards the
end of the last period to 1100 AD metallurgy and the drawing of wire through
die plates of various materials developed, but quality and quantity of wire made
little progress. With the invention of steam engines in the eighteenth century
the process of drawing was mechanised and made easier, utilising rollers to
both pull and smooth the wire, making it more consistent in quality. Despite
this progress, it was still expensive to produce and the quality of the metal was
inferior so that wire breakage was a continual problem. The first breakthrough
came in 1856 with Henry Bessemer's development of the converter which, with
further improvements ultimately led to high-quality steel during the 1860s. The
next breakthrough involved the mass extrusion, or drawing, of wire, as Delbert
Trew (2006, 5) in his article 'The Making of Wire' states:
Steel history states the Washburn & Moen Manufacturing Company is responsi-
ble for many innovations in the manufacture of wire. By 1870, the company had
developed a continuous wire rod mill allowing for unlimited production of wire
and had begun development of automatic reels needed to speed up production.
This could facilitate the quality and quantity of relatively cheap wire, sold in
rolls, that could supply the lengths required on a daily basis for a busy cutting-
shed, which is why we only begin to read of the wire-bladed bow-saw method
after this time.
The size of wire these brick cutters preferred, according to Richards (1901,
45) was No. 18 gauge, this size, in England, being the B.W.G. designation, which
meant Birmingham Wire Gauge and which was later superceded by Standard
Wire Gauge or S.W.G. A drawing of a bricklayer's bow saw, but then termed
a 'frame saw', is described and illustrated by Audel in Volume 1 of his North
American craft book, 'Audels Masons and Builders Guide' (1924, 101-2):
The saw consists of a frame holding the blade which is of twisted soft steel or mal-
leable iron wire (No. 16 B. w. g.).
Making a Twisted Wire Blade
The method of twisting wires varied, as would the wire diameter, 21 mig (metal
inert gas) welding wire gauge being favoured by the author, as a thinner wire
gives a finer cut. Some craftsmen cut two separate lengths of wire (typically
the length of the bow saw plus about 200 mm) and tie them off at either end.
