e covering of the second cylinder
along at fixed intervals, but they are complicated and troublesome.
These presses are expensive and cumbersome, and can generally be used
only for inferior grades of work in large editions. Under the care of
a skilful and painstaking pressman, good work can be produced from
them, but fine book-work is always done on stop-cylinder and
two-revolution, single-cylinder presses, which have now been brought
to a high state of perfection.

Nearly a hundred years ago Hansard wrote, "The printing machine in its
present state appears susceptible of little improvement." He was, in
truth, right so far as the main principles of the flat-bed cylinder
press are concerned, but there have been immense improvements in many
of the details. With the introduction of automatic sheet-feeding
devices, and improvements in the driving, inking, and delivery
arrangements, mechanical ingenuity seems to have been exhausted. The
temptation is strong to apply Hansard's prediction to the flat-bed
cylinder press of the present day, but with the many surprises that
meet us in other fields this would border on temerity.

Already there have been great advances in adapting the entirely rotary
principle to the printing of high-grade work, although its use is
still restricted to the production of large editions.

As early as 1852 Hoe & Co. made a rotary press for D. Appleton & Co.,
especially for printing the famous Webster spelling-book. The types
were locked up on the cylinders in curved beds, called "turtles," and
the sheets were delivered by a sheet-flier. Probably thirty million
copies were printed on this press, which was dismantled nearly
twenty-six years ago.

In 1886 this same concern made a press which is still used for
printing some of the forms of the _Century Magazine_. This press had
two pairs of cylinders, and curved electrotype plates were used on it.
The paper was in a roll at one end, and at the other end there were
delivered, to each revolution of the cylinders, eight eight-page
signatures already folded to the size of the _Century_ page. This was
the first rotary press made for a good grade of book-work. Two similar
presses were afterward made for _Harper's Weekly_ and for the _Strand
Magazine_ of London.

What is known as the rotary art press was made in 1890 for printing
the fine half-tone illustrations in the _Century Magazine_.

This has one plate cylinder and one impression cylinder, and curved