east of Pittsfield, and upon this, as well as upon the residue of the 341 miles between Henry's and the State line, the work has been vigorously prosecuted to the present time. The 28 miles between Connecticut River and Henry's in Chester, were put under contract for grading in April last, and as soon as was practicable after the passage of the act of the last Legislature; the contractors engag ing to complete the grading and masonry by the first of July, 1840. Upon the greater portion of this part of the line, the work was commenced in July succeeding, and the whole is now in progress. It is confidently believed, that the graduation and masonry will be finished in season for laying down the rails in the course of the present year. Preparations are also making for materials for the bridge across the Connecticut at Springfield; the lumber having already been contracted for. And the directors hope to finish the same, and to lay down the track for at least 20 miles westward of it, and open the same for use during the year. The graduation west of Pittsfield is nearly completed, with the exception of two sections. The cuts upon each of these proved to be much more difficult than was anticipated. The contractors have been always impeded by water, and in the winter months, by the constant freezing and thawing of the materials. On one of these sections the principal work, was entirely suspended during last winter from this cause. Upon another, the embankment has for a long distance settled from 40 to 45 feet below the natural surface of the meadow. And upon these, as well as some others in the vicinity the work has been entirely interrupted by the recent snows;the contractors having been obliged to employ their whole forces, in some instances, for two or three weeks in removing the same. This part of the road, however, being 11 miles, will be graded, the superstructure put upon it, and the whole opened to the public in the autumn of 1840. The undersigned anticipate, also, that a further portion of 10 miles of the road, east of Pittsfield, and extending eastward to the summit division, will be graded by the 1st of August next, with the exception of two sections in Hinsdale and Dalton. The contracts for these require them to be completed by the 1st of October, and they are already in a good state of forwardness. The remaining Summit Division of about 13 miles, extends from Henry's in Chester, through the gorge of the mountain, and over the summit in Washington, to the Hinsdale Meadows, embracing the whole range of the mountain pass. This is by far the most difficult and expensive work upon the whole line. And such have been the obstacles interposed by nature to our progress, that it may not be amiss to advert, briefly, to the extent and character of this part of the work. The west branch of the Westfield river, or the Pontoosuc, as it is now called, winds its way from the summit, by a rapid descent, down a narrow defile of the mountains, pursuing a very circuitous route, frequently turning the point of an abrupt rocky spur, only to be again thrown out of its course, by a similar spur upon the opposite bank, which, in turn, it is oblig ed to double by curving suddenly in another direction. The road follows up the general course of this stream to the summit. And in order to avoid excessive curvature, and to maintain uniform grades by a continuous ascent, the line of it necessarily crosses these spurs, successively. It passes them by heavy rock excavations, spanning the stream, often obliquely, and in some cases, at a height of 60 and 70 feet above the water, and with very heavy and expensive masonry. Within the 13 miles, the river is passed by 21 bridges, 9 of which are stone arches, and 3 of these are of 60, and 5 of them of 45 feet span; and they sustain embankments, severally, of 40, 37, 52, 62, 70, 60, 42 and 31 feet above the water. Many of these require also heavy bank or river walls, some of which are 60 and 70 feet in height. The embankments must, of course, in many instances, await the completion of the bridges and walls. The masonry has been pushed vigorously, and as much of it is in progress as can well be carried on at one time. On the 1st of December last, 15,300 perches of it, (of 25 feet,) were finished, and 37,500 were yet to be built; 25,000 of which, however, are bank walls; of earth 136,000 cubic yards, and 86,000 of rock, had been excavated, and 304,000 yards of earth, and 97,000 of rock, remained to be taken out. The Summit ridge is passed by a thorough cut above 2,600 feet long, and its deepest point 52 feet. About 57,000 cubic yards of this is estimated to be rock, and much of it is of the bardest kind. The whole material of the cut should come out in one direction, in order to form the large embankment east of it; and while the rock continues, but comparatively a small force can be employed upon it. The grade immediately east of the summit is at the rate of 77.6 feet per mile; and still farther east it is 79.9 feet for two miles. At the summit, the road bed is 1378 feet above the Springfield depot, and about 1440 feet above tide water at Boston. From present appearances, these summit sections will be the last work finished upon the line. In our report of last year it was stated, that in the condition in which it then was, no definite opinion could be formed, as to the time when it would be completed, and that this point could not reasonably be ascertained, before late in the year 1839, when the character of this rock cutting might be more clearly developed. The work is now so far advanced, as to justify an opinion, that the grading and masonry of this whole division may be finished in season for laying down the superstructure during the year 1841. The parts of the road west of the river, already graded at different intervals, are as follows: Between Springfield and Henry's in Chester, 5th Div. 4.5 miles do. do. west of to State line, From this view, it will be seen, that of the 62.6 miles of the road west of Connecticut river, if no unexpected obstacle interposes, about 50 miles may be graded and ready for the superstructure during the present year, viz., 21 miles at the westerly end, 28 miles at the easterly end, that by the same time the superstructure may be placed upon at least 11 miles of the westerly part, and 20 or more miles of the easterly part, and the same be opened for use, that in the spring of 1841, the rails may be laid upon all the residue, excepting some 10 miles of the summit division; which may be completed in all that year. Of the Iron for the superstructure, 3,500 tons have been purchased;about 2,000 tons of it have arrived, and the ballance for the whole line hav ing been ordered to be purchased, will be forthcoming, as the work may require it (To be continued.) In the number of the Journal for March 1, article on "Atmospheric resistance to locomotion on railroads, etc.," page 139, 17th line, for "palaces now flying," read, palaces now plying. Page 141, 4th line, for "Nos. 288 to 291 and 288," read Nos. 285, to 291 and 288. Last No. of the Journal, article on "Theory of the crank," page 205, 30th line, for "contrary varying motion," read continually varying motion. CIRCULAR. Addressed to the Engineers in the vicinity of, or resident in the city of New York-also to those in the habit of visiting New York, from time to time. NEW YORK, APRIL 15, 1840. At the solicitation of several professional gentlemen I have been induced to establish a Reading Room and Exchange for Civil Engineers. It is well known that, while every other profession has some one place, at least, in this city, for occasional meeting, and as a resort open to them at all times, Civil Engineers have hitherto been without this convenience. It is proposed to furnish the reading room with the various domestic and foreign scientific periodicals relating to the profession and also with papers from various parts of the Union. To increase the usefulness of such an establishment, the valuable collection of reports, documents, etc., belonging to the office of the American Railroud Journal, will be placed in the Reading Room, as also some of the most important professional treatises. It is understood that several gentlemen are willing to deposite various works for the benefit of the establishment. The number of Civil Engineers at any one time in the city, is much greater than is generally imagined, as the subscriber has often had occasion to remark. By the method proposed, these gentlemen would have frequent and easy intercommunication, and as Civil Engineers, from all parts of the Union, are frequently in the habit of visiting the city,it is conceived that, by the plan proposed, the interests of the profession would be in no slight degree advanced. The Reading Rcom will be attached to the office of the American Railroad Journal, and I pledge myself, in conjunction with Mr. Egbert Hedge, joint proprietor in that paper, to offer every facility in our power to accommodate gentlemen resorting thereto. Those gentlemen who choose so to do, can have boxes provided for the reception of letters and other communications; and strangers or visiters can have an arrangement made whereby all letters and papers addressed to them, while in the city, can be taken charge of. It is proposed to open the Reading Room on the first of May next. Your obedient servant, GEORGE C. SCHAEFFER, Editor American Railroad Journal. SEASONING TIMBER. Some time since we received the following note, which should have received attention in an earlier number. Circumstances have prevented us from taking it up until now, and as there are two totally distinct questions, we purpose to consider at present only the first, in the meanwhile soliciting communications on the subject from our readers. MR. EDITOR-Will you, or one of your readers, oblige me by an answer to these questions? 1. In what does the process called "seasoning" of wood consist? Is it in merely drying up the sap and evaporating the water contained in it? If so, can this be as well done by the heat of an oven or furnace, in a short time, as by exposure to the sun and air for a long time? 2. What is the Dutch mode of making the little yellow bricks of which the oldest houses of our city are composed? Is their color owing to the kind of clay used-the mode of burning them-or to both? Are they very much compressed in making, or to what cause is owing their great hardness and durability? Can bricks of such quality be made in this country, and what place furnishes clay of proper quality? I make these inquiries partly for obtaining information for my own use; and partly in the hope that they may lead others to think of the superiority of the Dutch brick, both as a matter of taste, as regards color, and of durability, (of both of which, I think, there is little room to doubt,) and thus promote the adoption of them in place of the crumbling, staring red bricks of which our cities are so generally built; and the chief qualities of which are, hardness to the eye, and softness under the mellowing hand of time. The process called "seasoning" is a twofold operation depending upon the constitution of living wood. In general terms, the wood of a tree con. tains fibrous matter, arranged in the form of minute vessels containing the sap. This sap is chiefly water, but contains besides a variety of soluble salts and organic matter. Wood taken in this, its green state, gradually contracts in bulk, and is, therefore, unfit to be used in any permanent construction. The watery particles may be expelled, or the wood dried by heat-and green wood baked in an oven is no longer liable to alter in dimensions; but a more serious evil is then met with. Wood when suddenly dried is cleft or "checked" so much, that in some kinds of timber, its parts may be pulled assunder as easily as if cleft by a wedge. The process must therefore, be gradual, so that the particles may have time, slowly to arrange themselves in a new order, which if suddenly assumed, would tear them from each other. This operation requires time, and hence we suppose the word "seasoning." The work of Duhamel, "Sur l'Exploitation des Bois," contains many excellent experiments and practical observations on this subject, a few of them with some additional information, may be found in "Barlow on the strength of materials." Duhamel gives an illustration of this process in the preparing of pottery ware for the oven. Vessels of any form, but more particularly solid cylinders, require a very gradual drying or they fall to pieces. The potters to avoid this, expose them in a cool situation, out of the sun for many days, and as the moisture very gradually flies off, the still soft clay has time to re-arrange itself without splitting. Now in wood the matter is less homogenous than in potters clay-and the density of the external and internal portions are never the same. Experiment proved that by delaying in a similar manner the drying of timber the danger of checking was greatly decreased. It was also found, as might be predicted, that when the wood was reduced while green, to a size near that intended for use, the liability to crack was removed, while a thorough seasoning took place in rather less time than when left in the original form. As a general rule, Duhamel states that timber grown in a rather dry soil is denser, harder, and stronger than that grown in a damp or marshy soil. Barlow also says that "generally in a sound tree the density is found to decrease from the butt upwards, and from the centre to the circumference. He likewise gives a table showing the difference in the loss of weight by drying, in their different portions. It follows from this, that a different period of time is necessary in seasoning different woods, or even different parts of the same tree. Barlow has a very interesting table of some experiments on the seasoning of English oak. Eight pieces of various size were cut from the tree and exposed on the beams of a smith's shop to a dry, but not warm air.—They were weighed at the commencement of the experiment, and afterwards at intervals for five years and a half. The total weight at the commencement was 9721 lbs., at the end 6301 |
