The device shown in the engraving employs only the swinging motion of the leg to generate the required power.

[Ill.u.s.tration: GOODES' IMPROVED TREADLE MOTION.]

A pendulum, A, is pivoted to the underside of the table and carries a heavy disk, B. To the central pivot of B is attached a foot piece, C.

The bottom of B is slotted, and through the slot pa.s.ses a stationary rod, D, which holds the bottom of the disk from vibrating while it causes the upper part to reciprocate with the swinging of A.

To the upper part of B is pivoted a pitman which actuates the crank as shown.

In operation the foot is placed upon the foot piece, and a swinging motion is imparted by it to the pendulum, which is ultimately converted into rotary motion by the crank as described. The heavy disk, B, gives steadiness to the motion, and acts in concert with the fly wheel on the crank shaft for this purpose; but it is not essential that this part of the device should be a disk; any equivalent may be subst.i.tuted for the same purpose.

Patented, through the Scientific American Patent Agency, Oct, 26, 1869, by E. A. Goodes For further information address Philadelphia Patent and Novelty Co., 717 Spring Garden street, Philadelphia, Pa.

Improved Method of Catching Curculios.

This is a novel and curious invention, made by Dr. Hull, of Alton, Ill., for the purpose of jarring off and catching the curculio from trees infested by this destructive insect. It is a barrow, with arms and braces covered with cloth, and having on one side a slot, which admits the stem of the tree. The curculio catcher, or machine, is run against the tree three or four times, with sufficient force to impart a jarring motion to all its parts. The operator then backs far enough to bring the machine to the center of the s.p.a.ce between the rows, turns round, and in like manner b.u.t.ts the tree in the opposite row. In this way a man may operate on three hundred trees per hour.

A bag and a broom are carried by the operator by which the insects are swept from the cloth and consigned to destruction.

[Ill.u.s.tration: CURCULIO CATCHER.]

Remains of a Megatherium in Ohio.

The Columbus _State Journal_, of Dec. 6, says "there is now on exhibition at the rooms of the State Board of Agriculture, or headquarters of the Geological Corps, a section of the femur or thigh bone of an animal of the mastodon species, the fossilized remains of which were recently discovered in Union county. These remains were found in a drift formation about three feet below the surface, and are similar to the remains of the Megatherium found in other parts of the State.

Arrangements were made by Mr. Klippart, of the Geological Corps, to have the skeleton or the parts thereof removed with proper care. Before excavations had proceeded far bad weather set in, and work has been abandoned. The section of the femur, upper part, with socket ball, is about twenty inches in length, or about half the length of the thigh bone. This would make the aggregate length of the bones of the leg about ten feet. The ball is twenty-two inches in circ.u.mference, and the bone lower down, of course, much larger. From the part of the skeleton secured, it is estimated that the hight of the animal was twelve and a half feet, and the skeleton entire much larger than the specimen now in the British Museum. As this particular species, or remains thereof, have been found only in Ohio, this specimen has been named the _Megatharium Ohioensis_. The animals lived, it is supposed, in the period immediately preceding the human period, and were after the elephant type."

Exhuming operations will be resumed in the spring, and if the skeleton is removed in good shape or a good state of preservation, it will be set up in the Echo room at the Capitol, where the fossils collected by the Geological Corps are now being arranged and stored.

Artificial Ivory.

A process for producing artificial ivory has been published in a German journal. The inventor makes a solution of india-rubber in chloroform and pa.s.ses chlorine gas through it. After this, he heats the solution to drive off any excess of chlorine, and also the solvent, whereupon he has left behind a pasty ma.s.s with which it is only necessary to incorporate sufficient precipitated carbonate of lime or sulphate of lead, or, indeed, any other dense white powder, to obtain a material which may be pressed into molds to form whatever articles may be desired. The details of this process are obviously incomplete, and the success of it may be doubted. Only good and well masticated rubber could be employed, and even then a dilute solution must be made, and any earthy impurities allowed to deposit. In the next place, we are doubtful of the bleaching action of chlorine on rubber, and, moreover, chloroform is, under some circ.u.mstances, decomposed by chlorine. Lastly, it is clear that, to obtain a hard material at all resembling ivory, it would be necessary to make a "hard cure," for which a considerable proportion of sulphur would be required. The simple purification of india-rubber by means of chloroform, would, however, furnish a ma.s.s of a very fair color.

An iron car made of cylindrical form is now used on the Bengal Railway, for the carriage of cotton and other produce. It is much lighter and safer than the ordinary car. We believe in iron cars.

ONE HUNDRED THOUSAND.--At the rate old subscribers are renewing, and new ones coming in, there is a prospect that our ambition to increase the circulation of this paper to one hundred thousand will be gratified.

AMERICAN AND ENGLISH RAILWAY PRACTICE CONTRASTED.

A paper on "American Locomotives and Rolling Stock," read before the Inst.i.tution of Civil Engineers, in England, with an abstract on the discussion thereon, has been forwarded to us by the publishers, William Clowes and Sons, Stamford street and Charing Cross, London.

We have seldom met with a pamphlet of greater interest and value. The whole subject of American as contrasted with English railroad practice is reviewed, and the differences which exist, with the necessities for such differences ably discussed. Mr. Colburn shows these differences to be external rather than fundamental, and traces many of the peculiarities of American construction to the "initiative of English engineers." The cause for the adoption and retention of these peculiarities he attributes to "the necessities of a new country and the comparative scarcity of capital," and thinks that but for these causes"

American railways and their rolling stock would have doubtless been constructed, as in other countries, upon English models, and worked, in most respects, upon English principles of management.

He reviews the origin and introduction of American features of railway practice, and points out as the distinguishing feature of American locomotives and rolling stock the bogie, or swiveling truck. "Keeping in mind the distinguishing merits of the bogie, the other differences between English and American locomotives are differences more of costume and of toilet than of vital principles of construction."

The author attributes the origin of the greater subdivision of rolling weight and consequent coupling of wheels on American roads to the comparatively weak and imperfect permanent way, estimating the maximum weight per wheel as being for many years four English tuns, while three tuns he considers, as more than the average for each coupled wheel of American locomotives.

To follow the author through the whole of his able paper, and the discussion which it elicited, would occupy more of our s.p.a.ce than we can spare for the purpose. We will, however, give in the author's own language, an account of an experiment conducted by him in 1855 on the Erie Railroad.

"In the autumn of 1855, the author, at the request of Mr. (now General) M'Callum, the manager of the Erie Railroad, took charge of an experimental train, which he ran over the whole length of the line and back, a total distance of nearly 900 miles. The same engine was employed throughout the run, occupying in all nearly three weeks, making an average for each week day of about 50 miles. The line is divided into four divisions, varying considerably in respect of gradients, and the utmost load the engine could draw was taken in both directions over each division. The maximum inclinations were 1 in 88. The results of the experiments were so voluminous, that it will be sufficient to detail the particulars of what may be termed crucial tests of adhesion and resistance to traction.

"The engine had four coupled wheels and a bogie, the total weight in working trim being 29 tuns, of which 17-7/8 tuns rested on the coupled wheels available for adhesion. The coupled wheels were 5 feet in diameter; the outside cylinders were 17 inches in diameter, and the stroke 24 inches. The safety valves were set to blow off at 130 lbs., and the steam, as observed by a Bourdon gage, was seldom allowed to exceed that limit. No indicator diagrams were taken, nor was any measure taken of the wood burnt, all that could be consumed by the engine, in maintaining the requisite steam, being supplied. The tender, loaded, weighed 181 tuns. The train drawn consisted of eight-wheel wagons fully loaded with deals. The average weight of each wagon was 5 tuns 8 cwt. 3 qrs., and of each wagon with its load 15 tuns 5 cwt. 3 qrs. nearly. The wagons had cast-iron chilled wheels, each 2 feet 6 inches in diameter, with inside journals 3 7/8 inches in diameter, and 8 inches long. All the wagons had been put in complete order, and the journals, fitted with oil-tight boxes, were kept well oiled. The gage of the line was 6 feet.

The weather was most favorable, clear and dry, with the exception of a single day of heavy rain.

"Upon about one hundred miles of the line, forming a portion of the Susquehanna division, a train of one hundred wagons, weighing, with engine and tender, 1,572 tuns was taken. The train was a few feet more than half a mile in length.

"At one point it was stopped where the line commenced an ascent of 24 feet in four miles, averaging 1 in 880 up for the whole distance. There were also long and easy curves upon this portion. The train was taken up and purposely stopped on the second mile, to be sure of starting again with no aid from momentum. The average speed was 5 miles an hour, and neither was the pressure of steam increased nor sand used except in starting from the stops purposely made. The engine, even were its full boiler pressure of 130 lbs. maintained as effective pressure upon the pistons throughout the whole length of their stroke, could not have exerted a tractive force greater than (17 x 17 x 130 lbs. x 2 ft.)/ 5 ft = 15,028 lbs.; nor is it at all probable that the effective cylinder pressure could have approached this limit by from 10 lbs. to 15 lbs. per square inch. Supposing, however, for the sake of a reductio ad absurdum, that the full boiler pressure had been maintained upon the pistons for the whole length of their strokes, the adhesion of the coupled driving wheels, not deducting the internal resistances of the engine, would have been 15028/40050 3/8 of the weight upon them. In any case there was a resistance of 4,011 lbs. due to gravity, and if even 120 lbs. mean effective cylinder pressure be a.s.sumed, corresponding to a total tractive force of 13,872 lbs., the quotient representing the rolling and other resistances, exclusive of gravity, would be but 6.27 lbs. per tun of the entire train; a resistance including all the internal resistances of the engine, the resistance of the curves, easy although they were, and the loss in accelerating and r.e.t.a.r.ding the train in starting and stopping. This estimate of resistance would correspond, at the observed speed of 5 miles an hour (upwards of of an hour having been consumed on the 4 miles), to 185 indicated H.P., which, with the driving wheels, making but 28 revolutions per minute, would be the utmost that an engine with but 1,038 square feet of heating surface could be expected to exert. This was the highest result observed during the three weeks'

trial, but one or two others are worthy of mention. On the Delaware division of the same line, the train, of 1,572 tuns' weight, was run over 5 consecutive miles of absolutely level line, at a mean rate of 9.23 miles an hour, and during the same day, over 5 other consecutive miles of level at a mean rate of 9.7 miles per hour. On both levels there were 14 chain curves of good length, and the speed, from 9 to 12 miles an hour, at which the train entered the respective levels, was not quite regularly maintained throughout the half hour expended in running over them. But if even 7 lbs. per tun of the total weight be taken as the resistance at these speeds, the tractive force will be 11,004 lbs., which is more than one fourth the adhesion weight of 40,050 lbs. On the next day, the same engine drew 30 wagons weighing 466 tuns, or, including engine and tender, 514 tuns nearly, up a gradient of 1 in 117, three miles long, at a mean speed of 10 miles an hour. The resistance due to gravity was 9,814 lbs., and supposing the other resistance to traction to amount to no more than 7 lbs. per tun, the total resistance would be 13,412 lbs., corresponding to a mean effective cylinder pressure of 117 lbs. per square inch, and to a co-efficient of adhesion of almost exactly one third.

"It is needless to repeat instances of much the same kind, as occurring during the experiment referred to. The author is bound to say that they were, no doubt, influenced by the favorable circ.u.mstances of weather, and something is to be allowed also for the great length of train drawn, very long trains having a less tractive resistance per tun on a level than short ones, and something, possibly more than is commonly supposed, may have been due to the use of oil-tight axle boxes, the saponaceous compound known as 'railway grease' being nowhere in use on railways in the States. It could not possibly be used, except in a congealed form, in the severe American winters; and Messrs. Guebhard and Dieudonne's experiments (_vide_ "De la resistance des trains et de la puissance des machines." 8vo. Paris, 1868, p. 36) made in 1867, on the Eastern Railway of France, showed a very considerable diminution in the resistance of oil-boxed rolling stock as compared with that fitted with grease boxes.

But, weighed upon the other hand, are the facts, first, that the line was of 6-feet gage, and, _pro tanto_, so much the worse for traction; secondly, that the wheels were comparatively small, and the inside journals of comparatively large diameter, the ratio of the former to the latter being as 7 to 1, instead of 12 to 1 as on English lines. It is difficult to believe that the length and steadiness of the double bogie goods wagons, scarcely liable as they are to lateral vibrations, had not something to do with the result, which is in some respects unique in the history of railway traction. The result, although not absolutely showing the real resistance to traction, nor the real adhesion of the engine, presents this alternative; namely, that the resistance must have been unusually small, or the adhesion unusually large."

In the discussion which followed some doubts were expressed as to the accuracy of Mr. Colburn's conclusions, drawn from the experiments described; but it was conceded by some who took part in the discussion that some of the features of our practice might be advantageously copied in England. For the most part, however, the opinion prevailed that the features of our system, which are here regarded as almost indispensable, could not be introduced into English practice with advantage.

BOILER COVERING.

BY C.M. O'HARA, C.E.