PRACTICAL PAPERS—IMPROVED MACHINERY. 
829 
These advantages have been secured for the saw with a 
straight edge, by Mr. Perin of Paris, by giving to the tool the 
form of a band running over pulleys, of diameter sufficiently 
large to allow the material to be operated upon to meet the 
saw on the descending side, without being interfered with by 
the part which is rising. The saw must of course be made of 
very flexible steel, and it is therefore comparatively thin. On 
its first introduction some disadvantage was experienced from 
this circumstance, on account of ’its unsteadiness. This, how¬ 
ever, has been overcome by the simple expedient of placing a 
fixed guide, which is nothing but a piece of wood having a 
slit in it equal to the thickness of the saw, immediately above 
the material which is to be cut. A similar guide is also usu¬ 
ally placed below. 
These band saws are constructed of various sizes, some of 
them sufficiently large to cut heavy timber. But the most in¬ 
teresting forms are those of which- the breadth is hardly greater 
than that of a watch spring. These are used to cut out scroll 
work, a function which they perform, whatever may be the de¬ 
gree of delicacy or intricacy of pattern, with surprising rapid¬ 
ity. Such saws were exhibited in both the British and the 
French sections of the exposition, and were constantly occu¬ 
pied in cutting out fanciful patterns for the gratification of 
visitors. Scrolls and spirals were cut out of blocks of hard 
mahogany four or five inches in depth, with very sharp curves, 
and of a thickness not exceeding that of very thin card-board. 
The initials of the names of the visitors were cut with great 
rapidity, in a very graceful script, and objects of this kind 
seemed to be especially popular. The object and the matrix 
are equally perfect; and owing to the very slight thickness of 
the tc>ol, the one fits neatly into the other and presents the 
pattern in relief. The band saw in this form is thus a very 
important addition to the resources of the ornamental worker 
in wood ; surpassing immensely in precision, as well as in rapid¬ 
ity of execution, any similar tool used in the hand. It is des¬ 
tined, doubtless, to come into very extensive use. 
When first introduced, this tool was not an immediate 
