« ZurückWeiter »
concerned in its settlement and history; with notices of distinguished individuals in other states.
III. Original Essays on literary and moral subjects; the « Lights and Shadows” of New-England life ; Sketches of Domestic Scenery, and of National Character ; Reviews of New Publications, and notices of Old and valuable neglected Works.
IV. Facts and Observations on any subject connected with the Useful Arts ; Experiments in Agriculture, and Improvements in Machinery; Inventions, Curiosities, &c.
V. The History of New Hampshire-being a continuation of Dr. Belknap's excellent work; also, a History of the Government of this State, with sundry important documents, copied by permission from the originals in the office of the Secretary of State. In the history of our State government, we shall present all the Messages and Speeches of the several Governors to the Legislature; and an impartial review of the proceedings of each Legislature, since the adoption of the Constitution.
VI. Poetry-original and selected; Anecdotes, &c.
VII. Statistical Tables; Meteorological Observations, and Facts relating to Climate.
VIII. AN APPENDIX: containing a faithful record of political events, and occurrences at home and abroad, which may interest or concern the people. Also, a monthly register of Marriages, Deathş, Casualties, &c.
Of the manner in which the work shall be conducted, it becomes us not to speak. We are assured of such assistance and aids, that we can confidently promise an interesting, if not a valuable miscellany. Of our own labors we would raise no expectations as we make no pretensions. We shall proceed with diligence and care, trusting that while we sustain the burthen of the experiment, willing and active pens will not be wanting. Our own exertions will be much directed to the preservation of the memorials of “olden time," and of those valuable historical and other documents which have been rescued from or yet remain in dust and ob$curity amid the rubbish of private families. Whether we succeed in continuing the work, depends upon the will of the people. Five hundred subscribers, punctual in their pay
ments, will enable us to proceed. And it surely ought not to be said, that among 240,000 inhabitants, five hundred cannot be found to encourage the attempt.
Reader!—We have spread our bill of fare' before you : if aught promises entertainment, you are welcome! If we succeed to please you—the credit shall be yours; if we fail -the fault shall not be ours.
JACOB B. MOORE. Concord, N. H. Jan. 1, 1823.
Useful inventions, &c.
Description of an improved Saw machine, with sectional teeth
for the purpose of manufacturing staves, heading and siding; with remarks on the machine, and the lumber manufactured by it by ROBERT EASTMAN, of Brunswick, Maine. With a Plate.
This machine consists of a frame about twenty four feet in length, and five in breadth ; and a carriage about twelve feet in length, and four in breadth. The carriage travels with iron trucks, grooved on their circumferences, which run upon iron slides bolted to the inner sides of the frame. An iron centre passes through one end of the carriage, and into the end of the log, and is one of the centres, on which it revolves. At the other end of the carriage, where there are two cross pieces, is an iron arbor, which receives the circular iron index with concentric circles of holes drilled at equal distances and corresponding to the different sizes of the logs to be manufactured into staves, heading, or siding. These holes are called the numbers of the index. On the end of the index arbor, inside of the carriage, is a square to receive a dog fitted to it, which is first driven into the end of the log, and then slipped on the square of the index arbor, by means whereof the index and log are firmly connected together, and both revolve on the index arbor and centre, which are kept in place by stirrup screws.
Near the middle of the frame is the main shaft, which is of cast iron, and runs on friction rollers, supported by stands on the floor. On this shaft are the saw and sappers, which are firmly attached to it with screws. The sappers which are crooked pieces of iron, steel edged, with slits to set them at a greater or less distance from the centre, according to the width of the lumber to be manufactured, and partaking of a common motion with the saw, only at a less distance from the centre, cut the sap off the log leaving the thick or outer edges of the lumber perfectly straight.
A band passing round the main pulley, wbich is on the main shaft, and on a drum that runs under it, (which may be driven by a horse, steam, or water power,) gives motion to the saw, and sets the machine in operation. The saw has only section teeth, and is made of a circular piece of sheet iron or steel, about one eighth of an inch in thickness, containing usually but eight teeth which are set in the outer edge of the saw plate, being dove-tailed and grooved in order to remain firm until worn out, when new ones may be set in the same plate.
Under the frame is a small sbaft with a large pulley on it (inside of the frame) which is connected to the main shaft by a band; on the other end of this small shaft at the outside of the frame, is another small pulley, which is also connected by a band to the feed pulley, which is placed near the middle of the frame. On the inside face of this feed pulley, are two wheels ; one of them containing eight cogs, is placed in the centre; the other a squirrel wheel, contains fifty cogs on the inside of its rim pointed towards the centre. Another short sbaft, containing two wheels of about eighteen cogs each, is placed near the middle of the frame; one of these wheels mashes into the rack under the carriage; the other is placed on the outer end of the shaft to be acted upon by the large and small wheels that are on the feed pulley, which causes the carriage to feed and return alternately by the different acting of the eight and fifty cog wheels on the 18 cog wheel, which not only reverses the motion, but, at the same time, gives a different speed to the travel of the carriage, in its feeding and returning. Thus when the 8 cog wheel mashes into the 18 cog wheel, the carriage moves forward with a slow motion to feed the saw: when the cut is performed, the feedpulley with its contents drops, unmashes the 8 and mashes the 50 into the 18 cog wheel, which reverses and quickens the travel of the carriage in returning, as 50 is to 8. This motion of the rising and falling of the feed pulley, is effected by a lever with a small steel spring at each end of it ; each spring has a catch to lock on a pin in the side of the frame, to hold the cog wheels in their mash, when the carriage is feeding and returning. In the centre of the lever is a pin, which attaches it to the side of the frame, and is the fulcrum
on which it works. On the top of this lever, are two wooden springs, which run from the centre to the end, a little rising, which forms an inclined plané.
A knob on the side of the carriage acts on the top of this wooden spring as the carriage is feeding and returning, and alternately unlocks the steel spring from the pin in the frame; and the wooden spring causes that end of the lever, where the knob is, to descend and the other to ascend, and locks its steel spring on the pin in the frame again. The piece of wood, which contains the feed pulley, is attached to that end of the lever which comes at the middle of the frame, and causes it to ascend or descend at every travel of the carriage. An iron frame is bolted firm on the end cross piece of the carriage, which holds an iron hand with a steel pointer in it, which, by means of a steel spring, locks into the holes of the index, and keeps the log firm in its place, while the saw is performing its cut.
On the inside of the end cross piece of the framć, is a shifting iron, which is a horizontal bar of iron with an elbow, forming an acute angle on the outer end ; on the inner end is another elbow, which turns down, forming a right angle, with a bar perforated with holes at suitable distances, to correspond with the numbers of the index ; into the holes in the bar a steel pointer 7 or 8 inches in length, may be screwed, so as to enter the holes of the index. This iron can move horizontally, being supported with hook bolts, and is kept in place by a small spring acting on the inner end; and two guard screws, are set, so as to guide the large pointer into one of the holes of the index when the carriage and log return from the cut.
On the other side of the frame, where the outer end of the hand on the carriage passes, is a small trip iron, that strikes on the outer end of the hand and unlocks its pointer from the index ; at the same time, the large pointer, entering one of the holes of the index and the carriage, striking the acute angle of the sbifting iron, gives it a horizontal motion inward, which causes the log and index to shift one number, when the shifting iron strikes the guard screw, that prevents its shifting more than one number at a time. The outer end of the hand being now relieved from the trip iron, its pointer enters a new hole of the index by means of the spring, and the carriage again moves forward for another cut.
Thus it operates, without any aid except the power that drives it, until it cuts a tier of lumber entirely around the log, like the radii of a circle, leaving their thin edges attached to