ruary 1827, and the work was commenced on the 4th of July 1828, by laying the corner stone of a monument near the rail-way, and a few months afterwards the road was actually begun, and has been prosecuted with great vigour. "It commences at the city block, in Baltimore, and passing thence to the depot, near the head of Pratt street, 1 mile, it is continued to the verge of the city plot, and thence to the Point of Rocks, on the Potomac river, a total distance from the City Block of 69 miles. At this point the progress of the work has been temporarily arrested, in consequence of the canal company having obtained a prior right of way. The length of the rail road, from the Point of Rocks to Pittsburgh, on the Ohio, will be about 260 miles at least: a reconnoissance of this part of the line has been made, but only a small portion of it has been surveyed. The road may, however, according to the charter, be conducted to some other point on the Ohio, between Pittsburgh, and the mouth of the Little Kenhaway. "The most difficult and expensive portion of this great rail-road is nearly finished, and in point of length it is surpassed by only three or four railroads in any part of the world. The eastern portion of the Pennsylvania rail-road (which will not be in operation throughout until December next) is only 15 miles longer. "In addition to the main line, extending 69 miles, a branch of three miles 130 poles, graded for a double, but laid with a single track, has been made to the city of Frederick. "The road bed is 26 feet wide. The grade for the first 29 miles from Baltimore does not exceed in any place an ascent of 22 feet per mile; on the next 11 miles, from 22 to 30 feet; on the next 3 or 4 miles, from 30 to 47 feet. At the distance of 40 miles from Baltimore, commences the first inclined plane, which ascends 80,375 feet in a length of 2,150 feet. The second inclined plane ascends 99 feet; the length is 3000 feet. The summit, (elevated 8131000 250 feet above mid tide), thus atattained, is 421000 54 miles from Baltimore. The line then descends by two inclined planes, Nos. 3 and 4. No. 3 is 3,200 feet long, and descends 159,63 feet. No. 4 is 1,900 feet long, and descends 81,35 feet. All the planes are straight. On the next five miles, the grade does not exceed 37 feet, except at two places, extending 1,176 feet, where it is 52 feet to the mile; the residue of the line to the Point of Rocks is much less steep. 1000 "The plan of the road presents numerous, and frequently abrupt curves. Of the 67 miles, extending from Baltimore, at the depot, to the Potomac, 33 miles and 615 feet, in the aggregate, are straight; 13 miles and 3,963 feet are composed of curves, the radii of which vary from 955 feet to infinity, and about 21 miles have radii varying from 395 to 955 feet; one curve, 1,400 feet long, has a radius of only 318 feet: another, 1,100 feet long, has a radius of 337 feet. On the branch, 2 miles and 1,034 feet are composed of straight lines-the minimum radius of curvature is 477 feet. maximum grade per mile is 30,0 feet. The "The viaducts are, with two exceptions, constructed entirely of masonry; these have materially increased the cost of the road, particularly on the first 13 miles, where they were adopted in preference to wooden superstructures, contrary to the opinions of the engineers. These viaducts are massive, imposing, magnificent, expensive, and injudicious structures. Dressed stone has been used in a few cases, thereby increasing the expense. The number of viaducts is 33, of which 31 are built entirely of stone; one of 12 feet span has stone abutments and a wooden superstructure; another, across the Monockessy, has three arches of 110 feet span each; the piers and abutments are of stone, the superstructure of wood, without a roof. "The Carrolton viaduct, near Baltimore, has an arch of 804 feet span, and a small arch of 20 feet span. "The Patterson viaduct, across the Patapsco, has two arches of 55 feet span, and two small arches (for roads) of 20 feet each. The Oliver viaduct has three arches of 20 feet span each. The residue of the viaducts have single spans: namely, three viaducts have spans of 10 feet; 10 have 12 feet; three have 14 feet; one has 15 feet; seven have 20 feet; three have 25 feet; one has 30 feet; and one has an arch of 40 feet span. "The masonry on the 71 miles 916 poles (including the branch) consisting of 80,303 perches has cost $318,072 and 41 cents; of which 58,244 perches of arched masonry cost $274,201 and 76 cents, and 22,058 perches of culverts, detached walls, &c., cost $43,870 and 65 cents. The additional cost of graduation, exclusive of masonry, is estimated in the last annual report at $783,542 and 84 cents; making the total sum, for graduation and masonry, of $1,101,615 and 25 cents, of which $30,258 and 914 cents is assigned as the cost of the branch. The first 13 miles constitute by far the most difficult and expensive portion of the line. The graduation of this part has cost $29,200, and the masonry $17,154 and 56 cents per mile; being $46,354 and 56 cents for these items alone. The cost of graduation of these 13 miles being $8,994 and 16 cents more than the cost of the remaining 54 miles; whilst the cost of the masonry on the first 8 miles only, is equal to the cost of the masonry on the remaining 583 miles; or the aggregate cost has been nearly in the proportion of 5 to 1. The first 13 miles present a continued series of stupendous embankments and excavations-an unusual proportion of the latter through rocks. "The cut near Baltimore is 70 feet deep; 310,250 cubic yards of earth were removed from it, at an expense of $122,118 and 33 cents. Gunpowder was used for the purpose of loosening the tenacious earth of this great excavation. "The great embankment across Gadsby's Run has a maximum elevation above the surface of 57 feet: it contains 210,101 cubic yards, and cost $65,584 and 35 cents. "The cost of graduation and masonry on the residue of the line is stated at only $8,532 and 16 cents per mile; and the total cost of the rail-road, on this extensive portion, at 20,168 per mile-a sum which the company state to be ample for the work in its farther progress to the west. The average cost for graduation, masonry, bridges, and rail-way, (composed of double tracks) has been on the whole line $27,128 per mile; but $30,000 will probably be required to defray all the expenses. "The rail-way is not uniform, stone sills, stone blocks, and wooden sleepers being used on different parts of the line. Forty miles of single track (equivalent to twenty of double track) are composed of granite sills, eight inches thick, 15 wide, and of various lengths: these are laid in trenches, filled with broken stone. This species of rail-way is used, at intervals, on the eastern slope of the road. The cost of it when completed, including iron, &c. will be about $12,500 per mile for the double track. The iron rail is attached too near to the inner edge of the stone, the bearing is not uniform, and the stability of the rail-way is impaired. On part of the Pennsylvania rail-road, where stone sills are used, this defect also exists; but it has been lessened by placing the iron rail nearer to the centre of the stone sill. "Six miles of single track are composed of stone blocks and wooden string-pieces, &c. similar to the Mauch Chunk and Cold Run rail-road, in Pennsylvania; the blocks on the former contain from one to two cubic feet, and are not one-third the size of those used on the latter, and they are laid in small detached pits, filled with broken stone, in lieu of trenches. The latter plan facilitates drainage. The pits, when unconnected with side drains, form receptacles for water in some soils. The blocks are four feet apart, from centre to centre. The whole of the residue of the line rests on wooden sleepers, which are not less than five inches thick at the smaller end, and frequently they are larger: they are also four feet apart, and are placed on broken stone, contained in pits, in the same manner as the blocks. The earth between the pits is not protected by broken stone: the action of the frost on it must, therefore, impair the stability of the sleepers. The wooden rails are secured by wedges, in the usual manner. The notches are, of course, wider at one end, but they are cut vertically. On the Little Schuylkill rail-way the notches are wider below than above; the wedges are less subject to displacement on the latter. The sleepers on the Baltimore and Ohio road are hewn out in the centre, to make room for the horse-path, and the greater portion of the wood work is covered by broken stone, earth, &c. The rail-way is thus rendered firmer, but the materials are more subject to decay. "The string-pieces are, throughout the line, six inches square, and the iron bars are 15 feet long, (pierced by 11 oblong holes) 24 inches wide, fiveeighths of an inch thick, and are cut off obliquely at the extremities. "The wheels of the wagons are made in accordance with the old fashioned plan formerly pursued on some of the colliery rail-roads in Great Britain -the felloe being slightly conical, and curving to wards the flange: this has, however, been claimed as a new and important invention. The novelty of rail-roads, in this country, has induced many ingenious persons, connected with this rail-road, to submit to the public, through the press, a number of devices purporting to be original; all of which (so far as they have been examined by the writer) are either in use, or have been proposed elsewhere, with two exceptions; namely, the mode of oiling the friction wheel of the wagon, claimed by Winans, and the plan of oiling common axles by means of a cork floating in oil; the latter was introduced by Colonel Long. Notwithstanding the frequent introduction of modern antiques," to public notice, through the medium of the Baltimore papers, the press of that city has rendered services of the greatest value and importance to the community, in sustaining the cause of rail-roads by much sound argument, and the promulgation of numerous facts. "The rail-road which has been described, is destined to confer as much prosperity on the city of Baltimore, as the enterprise of the company has already conferred reputation on her public-spirited citizens. "In addition to the works already mentioned, many rail-roads are in rapid progress. The first number in the list below indicates the extent proposed, the second, the number of miles finished, or that will be finished in the course of this year. "In Pennsylvania.-1. Philadelphia, Germantown, and Norristown rail-road, 18 (6 f.). "2. Little Schuylkill, 27 (22 f.). 3. Danville and Pottsville, 47 (11 f.). 6. Schuylkill Valley, 10 f. "8. Lykin's Valley, 16 f. "9. Carbondale and Honesdale, 163 f. "These roads have numerous small branches, which latter are not included. New Jersey.-10. Camden and Amboy, 61 (34) f.). "11. Patterson and Hudson, 16 (16 f.). "Delaware.-12. Newcastle and Frenchtown (16 f.). 13. Baltimore and Susquehannah, 70 (21 f.). "Virginia, &c.--14. Chesterfield (13 f.). 15. Petersburg and Roanoke, 60 (30 f.). "South Carolina.-16. Charleston and Hamburg, 135 (135 f.). "New York.-17. Harlem, 8 (8 f.). "18. Hudson and Mohawk (15† f.). 19. Schenectady and Saratoga (22 f.). 20. Ithaca and Owego, 29 (29 f.). "Massachusetts.-21. Boston and Lowell (— f.). "Kentucky.-22. Lexington and Louisville, 96 (15 f.). Many rail-roads will be commenced during this and the ensuing year; and every day adds to the number and magnitude of these popular projects. Charters have been granted for rail-roads extending in the aggregate 5460 miles, of which 1350 will be finished by 1833; but many of the works thus authorised will not be commenced. CLIMATE OF THE UNITED STATES. When North America began to be colonized by the northern nations of Europe, it was soon discovered that, in winter particularly, the temperature of the atmosphere in any given latitude was much more rigorous, than in like latitudes of Europe. Such difference excited a very natural astonishment, and as the real cause was unknown, many very fanciful, and some very absurd theories were formed to account for the phenomena.. Some of these theories may be seen under the head of Climate in the Art. America, Vol. I. page 582, and supra. Without pretending to decide a problem, demanding such extensive element for its complete solution, we proceed to state observed facts, and with very few comments leave the question to further discovery. Before, however, we proceed to arrange our data, we beg leave to observe that the climate of America, cannot be understood without being taken as a part of the atmospheric constitution of the whole earth; we therefore present the subject under two heads; Prevailing Winds, and Thermometrical Observation. Prevalent Winds.-Assuming the motion of the atmosphere, as arising from one general cause, and that motion as the true cause of climate, we place it before the results of observations made by the aid of the thermometer, which latter we trust to show are mere effects produced by the winds. TABLE XIX. Prevailing Winds, at various Points on the continent of North America, above N. Lat. 35. numbers reduced to proportions of 1000. The whole No. 21 was constructed from the Meteorological tables in Les Annales de Chimie et la Physique, and shows, that at Paris, during 3996 consecutive days, the winds from the western side of the meridian amounted to upwards of one half, and in several years to above four-sevenths of the whole aerial currents. Are not the orchards of France, similar to those of the United States, inclined to the eastward? Since the construction and publication of the preceding tables, the author of this article commenced a series of observation at his residence near Sandy Spring, Montgomery county, Maryland, from which the following table was constructed. TABLE XXII. Prevalent winds at the White Cottage, near Sandy Spring, N. Lat. 39° 11';-with monthly mean temp. It is evident, if we compare the Washington with any other table compiled from observations made in either the United States or north-western Europe, that some local cause must operate to give so great a proportion of northern winds at Washington City. In almost every table of winds which we have examined, it was a remarkable feature that the winds from N. and S. were rare and nearly balanced each other; and that those from E. and W. presented similar comparative phenomena. Correctly indeed, in deducing their influence on aerial temperature, the north wind ought to be combined with those from the three western points; but in the table constructed from observations at Sandy Spring, this combination was neglected from the unfrequency of northern winds. Without, however, taking the N. wind into account, the mean amount of those from the three western points, exceeds those from the five other points, as 566 is to 1000. Both in Europe and in the United States, the course of the winds and their relative frequency and intensity, have been attributed to the relations of land and water, but actual observation proves demonstrably, that the great aerial currents similar to the tides, are, though influenced by land and water, dependent for their origin and general course upon causes above the oceanic or terrestrial subdivisions of the earth. The volumes of this Encyclopædia contain data to settle this question, part of which, to save tedious reference, we trans VOL. XVIII.-PART I. cribe and present to the reader as part of this article. "The third branch of the meteorology of Eng-. land, respects the WINDS.* It has already been remarked, in the general observations on the climate of this country, that the W. and S. W. are much more prevalent as well as constant, than the winds from any other quarter; and this circumstance may easily and naturally be accounted for, from the situation of the island, exposed to the Atlantic Ocean. The W. and S.W winds are also the most violent, not only on the western side of the country, but also in the midland and eastern counties: so much so indeed, that the effects of their constancy and violence may generally be traced in the evident bending which they have given to the trees, in all parts of the country." It is no presumption to say that the actual phenomenon was known to the writer of the above extract, but the cause not even suspected. In Darby's View of the United States, page 424, it is remarked, 66 so constantly do the prevailing currents of air set from the west over the continent of North America, that the orchards and forests generally, particularly along the Atlantic slope, invariably incline to the eastward or south-eastward. This interesting phenomenon may be seen by any person travelling along the roads, and it is in an especial manner discernible, if the traveller is passing in an E. or W. direction. on A prevalence of winds towards the ocean North America, and from it on the British islands, must certainly depend upon some more general cause than mere oceanic approach. But we proceed with our extracts. "From the observations made by order of the Royal Society, it was ascertained, that, at London, the state of the wind was as follows: S.W. S.E. N.E. E. N.W. S. W. N. 112 32 58 26 50 18 53 16." From these elements, the western winds prevail at London, 215 days in the year, and are to the winds from all other points as 589 to 1000, affording an astonishing accordance with the aerial phenomena over the middle and northern part of North America. At Liverpool, from the observations made by Mr. Hutchinson, the winds prevail from N. N.E. E. S.E. S. S. W. W. N.W. 13 29 18 115 9 54 49 58 western winds as 441 to 1000 of the whole. "From these results it appears, that at Liverpool the wind blows more frequently from the S.E. than from any other point; and this circumstance at first sight may be deemed to contradict the general observations which we affirmed on the most prevalent winds in England: but Dr. Darwin, as well as Dr. Garnett, very satisfactorily ascribe this remarkable deviation at Liverpool to some atmospheric eddy, produced by the situation of the place. Enc. Vol. VIII. page 125. "Upon an average of three years, it was ascer |