MACHINERY AND PROCESSES. 137
better and firmer stitch, elimination of vibration, and quietness of
operation.
The life of a plain sewing machine is estimated at from 10 to 15
years, depending on the care and the amount of repairs put upon
it, but special machines wear out or become obsolete in a shorter time.
The depreciation on all the machinery in a muslin-underwear factory
may be fairly estimated at 10 per cent per annum.
Special tucking devices to make as many as 12 tucks at one time
have been invented.
The slow and tedious process of hemstitching, formerly done by
hand, is now done on fine materials by 5 to 12 needle hemstitching
machines.
The same progress has taken place in overseaming and zigzag stitch-
ing by machines, thereby allowing the of a finest laces and
embroideries to the sheerest of materials.
The same can be said about the process of ruffling, which is easily
accomplished by attaching ruffling blades to the machines. The
attachments complete a ruffled Thoda at one operation, which
under the old system consisted of several operations, consumed much
time, and required expensive handling of goods.
A strip folder and guide or a tape guide is used, whereby a strip
is folded and stitched or a tape is laid and stitched on over the edge
of the ruffle.
Buttonholes were formerly made by hand. The marks were made
by the worker and a knife-like device was used to cut the hole in the
cloth. The machines to-day make straight buttonholes at a speed of
about 1,600 stitches per minute. The form of the stitch, whether
purl or whip, barred ends or ends without bars, depends on the
attachment used.
Button Sing by hand is done quite extensively at the present
time, but is gradually being replaced by button sewing by machines.
These machines have automatic thread-tieing and thread-cutting
devices. They are capable of making from 900 to 1,000 stitches per
minute. Skilied operators can sew on about 7,000 or 8,000 buttons
daily. Clamps on the machines hold the buttons and can be adjusted
to any required size.
The same line of development has taken place in the embroidery
machines. These are as imported, Germany being the chief pro-
ducer of these machines. Within recent years, however, American
machine manufacturers have invented a number of machines for
scalloping and embroidering. These machines produce a variety of
styles of embroidery in flowers, leaves, and other el Skilled
operators are required to manage these machines. The cloth is
stamped with the design, then placed in a hoop and under the needle.
The hoop is then guided by the operator to carry out the design of the
embroidery on the goods.
The number of cutting and sewing machines owned by the 65 estab-
lishments reporting data, the investment in machinery, and other
items are shown in Table 42, which follows: