Messrs. Editors:--I am a reader of your valuable paper and find in it much to interest, and many practical hints that are useful in my vocation; I would not be without it for any consideration and I think every mechanic in the land should take it, read it, and profit by the reading.

I notice, in Vol. XXI, page 371, a communication headed, "Watch Repairers' Shop," in which directions are given to fill the c.h.i.n.ks in the floor around the work-bench with soft pine and putty, etc., etc.; this is all well enough, but will not prevent the breaking of pivots should a balance wheel be dropped, neither will it prevent the wheel being stepped upon and so rendered useless, as often happens.

I am a watch-maker and jeweler, and I never drop a wheel or part of a watch on the floor. I have an ap.r.o.n about one yard wide, and in the corners of it are eyelet-holes, so that I can pin it to the bench when I am working; I have strings to it, but do not generally tie them around me, but let it be loose in my lap as I have to jump up, to attend to customers in the shop. In the shop where I learned my trade (in London, England), every workman was _compelled_ to wear an ap.r.o.n, and so much waste of property and valuable time was saved; the saving of _time_ in _one week_ will more than pay the cost of the ap.r.o.ns.

Sidney Plains, N. Y,

GEO. C.L. KENT.

Western Demand for Agricultural Implements.

Messrs. Editors:--I often think, on perusing your very valuable journal of science, and the numerous mechanical and scientific problems it unfolds, that the tendency of the age is to supersede all manual labor by machinery. Whether such a thing is possible is not the question for me to consider; I only know that the tendency of universal human genius seems directed to that end.

I make the above observation casually, in order to introduce a few ideas on the subject of improvement in agricultural implements--the great _desideratum_ of the West at this moment. Here nature has opened her stores so munificently, that all the husbandman has to do is to plow, sow, and garner the fruits of his labor. But two great improvements are needed to enable the western farmer to keep pace with improvements in the mechanic arts and other kindred employment. Indeed, we at the West, particularly, need a good, cheap, steam plow that can be made practicable for at least the better grade of farmers. The English plan of moldboards, that overcome all possible traction and necessitate the duplex stationary engines, with the c.u.mbrous "artillery of attachments,"

may do for sluggish people but will never meet the wants of the Yankee nation.

The steam plow suited to the genius of our people, must, to use a vulgarism, "get up and go." It must possess sufficient power of propulsion and traction to pulverize the ground better, deeper, and more rapidly than the "old way." Such is the want of the great West in reference to preparing the soil for crops. I do not know of such a machine in use, nor do I believe in the theory of Dr. Brainard, that the moldboard is the only plan for properly pulverizing the soil; for I am satisfied that such plan is wholly inadmissible in steam plowing in this country, for want of sufficient traction for self-propulsion, and observation has taught me that a self-propelling plow is the only steam plow our people will tolerate.

I have lately examined the drawings of a steam plow invented by a gentleman of this city (which I am not at liberty to explain in detail) that seems to meet the great want I have spoken of. The invention consists in a very simple device, by which the whole force of pulverizing the ground is applied to propel the machine, and if this be not sufficient, an independent force may be applied, so arranged as to govern the speed of the machine at the will of the operator. You will, no doubt, in due time hear more of this machine, which seems to me to meet the great want so long experienced in Western cultivation.

The next great want of the West is a practical grain binder, that shall securely bind the grain as cut. The scarcity and high price of labor renders such a machine an absolute necessity. The efforts to supply this great want have been numerous, but with no flattering success so far as I am able to learn, except the machine invented by a citizen of this place, which has already made its mark by demonstrating that automatic machinery can and does bind the grain as fast as cut. The machine I speak of is yet in a chrysalis state, so to speak, but it has been worked two years in the field, the last season without missing a bundle, though not without the usual difficulties of all new machines in respect to the workings of some parts--too weak, etc. It is believed that the coming harvest will witness its triumphant success. If so, the production of our staple cereal will be greatly cheapened. I shall be glad to renew "old acquaintance," by a more detailed statement hereafter.

I send enclosed the pay for another year of the SCIENTIFIC AMERICAN, which I can no more do without than my accustomed dinner.

C.

Madison, Wis.

Economical Steam Engine.

Messrs. Editors:--Permit me now to make a few remarks in regard to an article on page 844, last volume of the SCIENTIFIC AMERICAN, ent.i.tled "Which is the Most Economical Steam Engine?" The principles laid down in that article, I think are correct.

I run a saw-mill with an engine which fills those conditions nearer than I ever saw, and I would like to give your readers a brief description of it. The cylinder is 10-inch bore, and 14-inch stroke; steam chest extends enough beyond the ends of the cylinder so that the steam travels only 2 inches, the shortest distance possible, after leaving the valve before it reaches the piston-head, and the s.p.a.ce between the piston-head and cylinder-head is only one-fourth of an inch, the bolt heads being counter-sunk until even. Other things about this engine are in proportion. With this engine attached to a direct acting circular mill, I can saw 2,000 feet of hard-wood inch boards in one hour.

If any of your readers can beat this, I would like to hear from them.

JOHN CARNES.

Friction and Percussion.

Messrs. Editors:--In reply to "Spectrum," page 358, of last volume, I will be brief. In his third paragraph he claims that he has merely _suggested_ that friction and percussion may often be one and the same thing; and immediately claims that in the case of the polished b.u.t.ton rubbing a planed pine board, the force which overcomes and levels the undulations of the wood, is percussion, and that percussion is also the cause of the heat; the microscopic hills and hollows on the shining bra.s.s b.u.t.ton skipping and jumping along the pine, produces little infinitesimal b.u.mpings, and so pound out the heat. This _little_ theory should be known to the homeopaths--they could ill.u.s.trate infinitesimal quant.i.ties by it!

"Spectrum" treats my hammered horsenail ill.u.s.tration shabbily. After indirectly acknowledging that there is a point where hammering will no longer produce heat, he puts it on the grindstone, subjects it to friction, and when it burns his fingers, throws his hat in the air and shouts "Hurrah for _percussion!_" We agree perfectly, except that he calls hammering, _condensation_; calls friction, _percussion_; and drops friction from the mechanical dictionary altogether.

A railway car axle often heats and sets fire to the packing, when the journal is smooth as polished gla.s.s; but I never heard of those parts of the car which are constantly undergoing percussion, even getting uncomfortably warm. The natives of the South Pacific produce fire by rubbing pieces of dry wood together, but I never heard of their rapping sticks for the same purpose. I have seen a new, sharp knife made hot enough to raise a blister, whittling a clean dry stick of pine, and I would like to have "Spectrum" tell us, if in all the above cases percussion is the cause of the evolution of of heat, and what is friction doing in the mean time.

New Albany, Ind.

C.C.H.

Oiling a Preservative of Brown Stone.

Messrs. Editors:--I have read the article ent.i.tled, "What is to Become of our Brown Stone Fronts," and have waited to see what others have to say. But with so much at stake, no body seems to know what to do or say.

Being a practical painter, it has been my lot to oil some of the best fronts in New York, namely corner of 23d Street and 5th Avenue, No. 2, West 23rd Street, also No. 1, West 30th Street; also the residence of E.S. Higgins, the carpet manufacturer, done by other journeymen.

They were very dark in color for a few weeks, but now after two years, they are bleached almost as light as they were at first.

These fronts were cleaned whenever necessary, and then oiled with fresh raw linseed oil from the press, put on pretty much as carefully as in ordinary varnish work. No second coat or lapping over of the oil. All was put on at once that it would take without running down in streams.

The result: the oil penetrates into good dry stone probably 1 inches, making the stone hard and flinty, as any stone cutter will soon find out if he tries to trim it.

It keeps the damp and therefore the frost out of the stone, as will be seen any foggy day, the damp running down in streams on the oiled stone, and the unoiled stone absorbing the dampness. It is therefore necessary to oil during dry weather.

The oil is especially beneficial to bal.u.s.trades and carvings, as they are generally got out of soft stone. It is also beneficial underneath balconies and porches, as the sun never has a chance to dry the stone in such situations before the frost flakes it.

This I send in part payment for the great deal I have learned from your paper.

T.H. Rilley

New York City.