1 4 , 4 , 
AMERICAN AGRICULTURIST. 
[April, 
Saws and How to Use Them. 
The idea of a saw was probably first suggested 
to mankind by a jagged edged knife. Some 
insects are provided with very perfect saws, such 
as, for instance, the well known seventeen-year 
locusts, the saw flies, and the wood wasps. Insects 
were, in fact, the first sawyers, and sawed for their 
existence ages before a human being thought of a 
saw. A Grecian story relates that an uncle, Daeda¬ 
lus, and his nephew, Talus, invented the saw al¬ 
most simultaneously by first discovering that the 
jaw bone of a snake could be used for cutting 
wood, and improved upon the idea by notching an 
iron plate. As in modern times, each one of these 
inventors claimed priority, and there being no 
patent office to appeal to, the uncle decided the 
dispute in the old fashion way by killing his nephew, 
which was a summary and effective manner of 
settling what a patent lawyer would now call an 
“ interference.” Ovid, who is known for his 
Fig. 2.— A JAPANESE SAW. 
doubtful way of giving facts, states that one Perdix, 
another nephew of Daedalus, made the discovery by 
using the back-bone of a fish, and was changed to 
a Partridge by some jealous rival ; it is not stated 
whether his rival plucked him clean, as is done 
Fig. 3.— A KEY-HOLE* SAW. 
now sometimes. Then, as now, we see that the 
inventive faculty seemed to run in families. Saws 
were made in what is known as the stoue age, when 
Fig. 4.— KEY-HOLE SAW NO. 2. 
only stone tools were in use, by cementing sharp 
flakes of flint into wooden handles. Saws of a very 
hard and glassy volcanic stone, known as Obsidian, 
have been found in New Jersey under several feet 
of gravel. Saws of the bronze age have been found 
in Germany. After bronze, iron came into use, 
and saws (very much like ours of the present day) 
were employed by the Egyptians. A saw found 
in the ruins of Thebes, and now in the British 
Museum, is represented at figure 1, and some old 
writers of nearly 2,000 years ago are supposed to 
have known of circular saws. The saw in figure 1 
is fastened into the handle by means of a tang, as 
our knife blades are. Saws are frequently men¬ 
tioned in Scripture, and 
stone, even, was cut 
with saws for Solomon’s 
temple. The fact is, 
that every form of 
Fig, 5. modem saw which is 
supposed to be of the 
very latest invention, has been known for many 
ages; circular saws were in use in 1777, and even 
the supposed to be recent band saw was patented 
in England in 1808. Besides, some very old saws 
are much better, and made on more correct princi¬ 
ples than our modern ones. For instance, who has 
not been annoyed when 
using a key-hole saw to 
find the blade catch and 
bend nearly double, and 
sometimes snap off as it 
is pushed through the Fig. 6. 
wood. But the Japanese and Chinese, and other 
Asiatics, have used saws of this kind for centuries 
that are free from this objection. At figure 2 is 
shown a Japanese saw that was used by a Japanese 
mechanic at the Centennial Exhibition. The teeth 
are seen to be inclined in a direction contrary to 
our usual method, and a key-hole saw thus made 
(fig. 3) could not possibly bend or break while in 
use, as that shown at 
figure 4 would certainly 
do in the hands of one 
that was not an expert 
in the use of saws. 
With this exception, 
our saws are now more 
effective than saws ever were, because the principle 
upon which the teeth work is well understood. 
The teeth are used first to cut, then to open an 
easy channel in which to work, and lastly, to re¬ 
move the chips or saw¬ 
dust. The form of the 
teeth and the “set,” or 
bend given to them, en¬ 
able them to perform 
these operations proper¬ 
ly. The best form, of course, has been discovered by 
gradual experience. If a novice attempts to cut a 
board across the grain with a rip-saw, he will find ' 
out that the shape of the teeth has much to do 
with the work, and that for cross-cutting and cut¬ 
ting along the board in the direction of the fibres, 
differently shaped teeth are required. A cross-cut 
saw cuts across the fibres of the wood, and sharp- 
edged teeth, filed to sharp points, so as to tear the 
fibres apart, are required. These teeth are triangu¬ 
lar, and are most frequently cut at an angle of CO 
degrees (fig. 5), and sometimes at an angle of 50 
degrees (fig. 6). For greater ease in sharpening, 
the form of the tooth has been changed in mill 
saws, as shown at figure 7, and this, by degrees, 
was improved to the “ briar-tooth,” figure 8, which 
is well adapted for the scraping or paring action 
used in rip-sawing timber. In ripping, a sharp 
chisel-like cut is made along the fibres, and the 
piece pared off is wedged out of its place by the 
teeth, the fibres having little adherence together 
as they lay side by side. This may be readily 
seen by the ease with which a board may be split 
lengthwise. This action is facilitated by the set of 
the teeth (fig. 9), each alternate tooth being bent 
outwards, so that the cut is wider than the blade 
of the saw. Formerly the teeth were bent over in 
sets of several at one side (fig. 9) alternately, but 
now each alternate tooth is set. Some sawyers 
upset or swage the teeth (fig. 10), which has the 
same effect as setting, but is better, because each 
tooth has two cutting corners. The teeth of a 
Fig. 9.— TEETH SETTING. 
Fig. 10. —SWAGED TEETH. 
cross-cut saw divide the fibres across, and reduce 
them to dust, the edges being sharp, to produce 
a clean cut (fig. 11). This is the M form of tooth, 
Fig. 11.— the m FORM OF TEETH. 
which was first described in 1846 in Germany, and 
it is, in fact, a doubled ordinary saw tooth, cutting 
both ways, and is therefore very rapid in its action. 
The teeth are usually set by bending the whole 
doubled tooth (fig. 12), but sometimes each half¬ 
tooth is bent alternately. This form of saw cuts 
iu a remarkably easy manner. Perhaps the most 
useful innovation iu sawing, is the use of the band 
saw, in which no back stroke is made, but a contin¬ 
uous down-stroke of a thin saw-plate, which runs 
over two large pulleys. This is an improvement on 
the circular saw, which has also a continuous mo¬ 
tion, as the band is always tight and rigid, and does 
Fig. 8. 
not spring as a circular saw sometimes will (into a 
dish form,) by the heating and expansion of the 
outer portion of the disc. 
As saws are wasted by filing, the space between 
the teeth is removed by “ gumming,” which is cut¬ 
ting away the metal, or punching it out. To ren- 
Fig. 12.— showing the setting. 
der this operation easier, some saws are made 
with holes in the lines of the “ gullets ” 
(fig. 13); rounded gullets are stronger than acute 
angled ones, and do not crack as easily as the lat¬ 
ter do (fig. 14), and the holed saws are convenient, 
not only on this account, but because a crack that 
may start, will not go beyond the first hole. For 
the purpose of clearing the saw-dust, a few teeth 
are sometimes left without set, and filed shorter 
than the others, but this is not necessary if ample 
room is left in the gullet to carry out the sawdust. 
American saws were formerly considered inferior to 
the English, but by care and skill in the manufac¬ 
ture, they are now superior to the English, and 
are largely exported to England. An American 
mechanic now insists upon having an American saw. 
Shell Marl, Oyster Lime, and Swamp Muck. 
The recent numbers of the Weekly Bulletin of 
the Connecticut Agricultural Experiment Station, 
under the able directorship of Professor S. W. 
Fig. 13.— holes in the “ gullets.” 
Johnson, have contained information of value to the 
general farmer. In the number for February 7th 
is an analysis of a Shell Marl which is shown to 
consist of 40 per cent of Carbonate of Lime and 
about 2 per cent of Carbonate of Magnesia, the 
remaining being mostly sand and moisture. 
“There can be no doubt that its employment, in 
liberal quantities, viz : one or .more tons per acre, 
especially upon grass lands, would often be at¬ 
tended with decided and long-continued benefit, 
but, in most cases, its action upon grain crops 
would not appear at once in so decided a manner 
as is very commonly the case with good super¬ 
phosphates or guanos. 
“ The fertilizing effects of this Shell Marl, as well 
as its commercial value, may be safely measured by 
the percentage of lime which it contains.” 
It is proposed to put this marl on the market as 
a fertilizer at $15 per ton, a price that js far more 
than the material is worth. 
The analyses of Oyster-Shell Lime, of which three 
are given in the same Bulletin, show that the prin¬ 
cipal constituents are Carbonate of Lime and 
Hydrate of Lime, with small quantities of Potash, 
Soda, Magnesia, and Phosphoric Acid. 
“ When applied to land, oyster-shell lime may 
act as fertilizer strictly speaking, or as an amend¬ 
ment. Commonly, both kinds of action are exerted, 
and the distinction between fertilizer and amend¬ 
ment is not generally recognized in practice, 
although very important in considering the effects 
of this substance. Lime is used as an amendment 
on heavy clay soils, 2 to 3 or more tons being some¬ 
times applied per acre. On loams or light lands 
Fig. 14.— SHOWING A CRACK. 
1,000 pounds, or 20 bushels of Oyster-Shell Lime, 
applied once in two or three years, is a usual 
application, equivalent to the addition of 300 to 
