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will vary, according to latitude and other circumstances, from the end of April to the beginning of July. Wet seasons and damp localities are prejudicial to the bark, and lessen its tapning power. The bark of southern oaks and of such as grow in high elevated positions is more rich in tannin than that of low and badly drained, damp, and shady locations. In hemlock bark the inner layer contains about 8 per cent of tannin, the middle part about 5 per cent, and the outer part about 34 per cent.
STRENGTH OF GLASS. A series of interesting experiments has recently been made in England, in regard to the tenacity, strength, &c., of glass. The experiments upon the direct tenacity of glass made by tearing specimens asunder, were less satisfactory or
reliable than others; and it is stated that more reliance is to be placed upon the • tenacity deduced from the experiments on the resistance of globes to bursting,
than upon the tepacity obtained directly by tearing specimens asunder. The latter method gave the following mean results of tenacity per square inch, in pounds :— Flint glass, 2,413; green glass, 2,896 ; crown glass, 2,916. The experiments in regard to the resistance of glass to crushing, were made upon small cylinders and cubes of glass crushed between parallel steel surfaces by means of a lever. The cylinders were cut of the required length from rods drawn to the required diameter, when molten and then annealed, in this way retaining the exterior and first coated skin of glass. The cubes were cut from much larger portions, and were, in consequence, probably in a less perfect condition as regards annealing. The specimens were crusbed almost to powder by the violence of the concussion ; it appeared, however, that the fracture occurred in vertical planes, splitting up the specimen in all directions. Cracks were noticed to form some time before the specimen finally gave way; then these rapidly increased in number, splitting the glass into inpumerable prisms, which finally bent or broke, and the specimen was destroyed. The mean resistance to crushing of the flint glass, was, in pounds, 13,190; of green glass, 20,206 ; of crown glass, 21,867.
HEAT OF DIFFERENT WOODS. The following is set down as the relative heating values of different kinds of American wood :- Shellbark hickory, being taken as the highest standard, 100; pig-put-bickory, 95; white-oak, 84; white-ash, 77; dog-wood, 75; scrub-oak, 73 ; white-bazel, 72; apple-tree, 70; red-oak, 69; white beech, 65 ; black-walnut, 66; black-birch, 62 ; yellow-oak, 60; bard-maple, 59; white-elm, 58 ; redcedar, 50; wild-cherry, 55 ; yellow-pine, 54; chestnut, 52 ; yellow-poplar, 52 ; butternut, 52 ; white-birch, 49 ; white-pine, 42.
Some woods are softer and lighter than others, the hard and heavier having their fibers more densely packed together. But the same species of wood may vary in density according to the conditions of its growth. Those woods which grow in forests, or in rich wet grounds, are less consolidated than such as stand in open fields, or grow slowly upon dry, barren soils. There are two stages in the burning of the wood. In the first, the heat comes chiefly from flame; in the second, from red hot coals. Soft woods are much more active in the first stage than the hard, and hard woods more active in the second stage than soft. The soft woods burn with a voluminous flame, and leave but little coal, while hard woods produce less flame and a larger mass of coal.
SORGHO DYE. A. WINTER, of Austria, has discovered a carmine-coloring matter in most parts of the Chinese sorgho, especially in the expressed stem, and has obtained a patent in Austria, Baden, and other States. The process is as follows :—The sorgho is pressed in the usual manner, and the empty cane piled up under cover in regular heaps, several feet bigh, and the fermentation which immediately sets in is so directed by more or less access of air as to prevent it from becoming putrid. After two weeks the whole mass is of a reddish brown or red color, when the fermentation is interrupted by drying. When dry, the mass is ground sufficiently fine for the extraction of the coloring matter. It is covered in the proper vessels with cold soft water, and allowed to stand for twelve hours ; but little of the pigment dissolves during that time. It is then drained and afterwards treated with a weak caustic soda or potash lye until this no longer extracts anything. This solution is carefully neutralized with sulphuric acid, thus precipitating the coloring matter in red flakes, which, after settling, is washed with water, collected on filters, and dried. This color dissolves in alcohol, alkaline lyes, dilute acids, &c., and is employed for the dying of silks and woolens with the common tin mordants. The colors produced from it are said to be unchanged by light or by washing with warm soap-suds.
IRON WORKS IN THE UNITED STATES. From a table compiled by the American Iron Association, exhibiting the number of iron works, idle and in operation, in the United States, it appears that there are furnaces, rolling mills, or forges in twenty-five of the States of the Union, leaving but eight States destitute of iron works; these are Mississippi, Louisiana, Florida, Texas, Iowa, Minnesota, California, and Oregon, all upon the boundary or frontier. The following are the totals :
Rolling mills. 210 15
1,545 832 488 225 These produce annually about 840,000 tons of iron, the value of which, in an ordinary year, is fifty millions of dollars. Of this amount, the portion expended for labor alone is $35,000,000.
ARIZONA SILVER. The St. Louis Democrat of a late date remarks :—We had the pleasure last evening of a visit from Hon. SYLVESTER Mowry, lately elected delegate to Congress from Arizona. Lieut. Mowry arrived by the last overland stage, and is en route for Wasbington city. He brings with him about forty-six pounds of silver from that territory. It consists of various specimens, from the moulded plates to the common sample, as are found in Arizona-pure silver, after the mercury is expelled, reduced by amalgamation ; silver reduced by melting and run in sand moulds ; silver and copper ore, and a large quantity of rough silver ore from the mountains in the Rio Grande valley, twelve miles from the river, pear the celebrated Stevenson mine. The whole region promises a rich yield. The ores are principally argentiferous galena, and reduced to a pure plate at a very small cost.
RAILROAD, CANAL, AND STEAMBOAT STATISTICS.
1862 ... 1853 ...
WHAT THE ERIE CANAL BRINGS TO MARKET, The following statement, from page 30 of the Auditor's Report on Trade and Tonpage of the Canals for 1858, is of interest. It is an exhibit of the average cargoes of the boats, of the time necessary to make a passage, and the cost to bring a barrel of flour from Buffalo to Albany, of the lockages at Alexander's Lock, three miles west of Schenectady, and the total tons delivered at tide water from the Erie Canal, as follows :
States, State. Years. boat bany. of flour. both ways.
Tons. 1841... 41 9 $0 71 30,320 532,520 224,175 308,791 1844 ... 49 710 60 28,219 799.816 308,025 491,791 1847
104 077 43,957 1,431,252 812,840 618,212 1848 ...
9058 34,911 1,184,337 650,154 534,183 1849...
36,918 1,266,724 768,659 498,068 1850 ...
0 58 38,444 1,554,676 778,858 598,001 1851.
40,396 1,508,677 966,093 541,684 053 41,572 1,644,999 1,151,987 492,721
0 56 42,967 1,851,438 1,213,690 637,748 1854 94
0 52 35,981 1,702,693 1,100,526 602,167 1855 ... 92
30,873 1,420,715 1,092,876 327,839 1856 ... 100 8+ 0.60 31,223 1,587,130 1,212,550 874,580 1857 ... 100 81 046 22,182 1,117,199 919,998 197,201 1858 ...
81 0 34 23,474 1,496,687 1,273,099 223,588 The table shows, comparing 1847 with 1858–
1. That the average cargoes of the boats, large and small, coming to the Had son River, have about doubled.
2. That the time of the passage is nearly the same.
3. That the average total charge on a barrel of flour, which is assumed as the index of the average diminished charge op down freights, is about one-hall.
4. That the number of boats required to bring the property to market is, with double locks, but about one-half the number required in 1847, when the locks were single.
5. That the tops of property brought to market is about the same.
Though the average cargoes of the boats, which brought the 1,490,687 tons to the Hudson River in 1858, was only 126 tons, the Erie Canal is now capable of a boat of about 200 tons. It should be observed that the above statement does not include the tons of property which go from tide-water, nor the internal movement, but only what comes to market from the Erie Canal, whether derived from its borders, from Western States, or from the latteral canals.
So far as the Erie Canal is concerned, it is a striking feature of the exhibit, that with such an increase in the cargo of the boat, and such a diminution in charges, there should not be an average increase of delivery at market. The reduction of the rates of toll last year, probably accounts for its increase of 370,000 tons over the previous one, but still, with only about half the charges, it is 360,000 tons below 1853.
The striking feature of the exhibit is the decrease of the products of this State coming to market-only about one-sixth of what came from Western States, in the last year ; while six years ago it was one-half. The reduction of the rates of toll on the canal should tend to increase the total arrival at market, but it seems to operate only on property from Western States. It may be that the competition of the lands of the West, through the Erie Canal, crowds upon the dearer lands of this State.
FRANCE AND ITS RAILWAYS. The Constitutionnel publishes a long article on the works of general utility wbich the peace will enable France to undertake ; and among the rest specifies the new railway lines now in progress or in contemplation. It adverts with justifiable satisfaction to the rapidity with which such works have been executed in France, after an undue delay at first, and points to the fact that the extent of railway communication in the country is now greater than in Great Britain. It says :-“ France under the influence of the Imperial Government has been able to repair the time lost at first in discussions as to the mode of execution, and subsequently in political revolutions. We now possess 8,700 kilometres of railway, (the kilometre is five-eighths of a mile,) which have cost nearly 4,000,000,000 francs-of which 3,250,000,000 francs were raised by companies, and 750,000,000 by the State. But we bave still 7,000 kilometres to construct, and nearly 3,000,000,000 francs to disburse for them. Such is the object we have to attain during the new epoch of peace which is now commencing. And when we have accomplished that object France will have a greater length of railway than any other country in the world, as she will have 16,300 kilometres, whilst the United Kingdom of Great Britain will only have 15,500. But the same will not be the case with regard to the population or the superficial extent of territory. Thus when the great network shall be executed, France will only have 450 kilometres for every million of the population, whilst in Scotland the proportion will be 949 kilometres, in England 866, and in Belgium 482. There is, therefore, pothing rash in the projects which we are now endeavoring to carry out.”
FLORIDA RAILROADS. Very few out of our State, remarks the Pensacola Observer, and many even in it, are not aware of the rapid strides internal improvements have and are making. From the following synopsis of the number of miles graded and ironed, it will be seen that we are ahead of some of our sister States, and making rapid progress to overtake others. In January, 1855, we had twenty-one miles from Tallahassee to St. Mark's, of “common flat rail”—a poor apology for a railroad ; it has since been regraded and reironed with heavy rail; the Pensacola and Georgia is graded to the Suwannee, and is in process of rapid completion to Lake City-distance one hundred and six miles—twenty-eight miles ironed, and the iron purchased for the remaining seventy-eight miles; the Central is graded from Lake City to Jacksonville, sixty miles—forty miles ironed, and the iron purchased for the balance; the Florida is graded from Fernandina to Cedar Keys, one hundred and fifty-four miles—one hundred and twenty-two miles ironed, and the iron purchased for the remainder; the Florida end of the Alabama and Flordia Railroad, fifteen miles ironed, and the iron purchased for the remainder. So we have two hundred and twenty-six miles ironed, and three hundred and forty-one graded, and the iron purchased for one hundred and fifty eight miles more, besides the short branch from the Pensacola and Georgia Road to Monticello, of three miles, and the branch now being graded from the Florida Road to Ocala. We get from that excellent paper the Floridian, the distance above as to the roads finished and graded in the East and Middle Florida-correcting, however, its statement, by adding fifteen miles ironed and in tine running order from Pensacola in the direction of Montgomery, so that the persons at a distance may know the number of miles actually completed—as well as the additional fact (perhaps unknown to the Floridian and Journal) that the balance of the iron for our end of the Alabama and Florida Road is purchased, and is now on its way to our city.
From the above statement, it will be seen that our people are no laggards, but have accomplished as much, in fact more, in four-and-a-half years, than the same population have accomplished any where in the Union; and the additional fact must be taken into consideration, that we have as much, if pot more seaboard, than all the Atlantic States combined, and hence we are less dependent on railroads for home purposes than any other State ; but in order to have rapid and convenient intercourse with our sister States, and mutually benefit each by building up our seaboard cities, and giving them access to our fine harbors for their produce and importations, we have thus in so short a time, with a very small population, made giant strides in the line of railroads.
HIGH RAILROAD SPEEDS. A recent pumber of the London Engineer has a very well written article on the subject of railroad speeds, in the course of which it says :-“For anything that can be seen, a speed of 30 miles per hour upon the water is practically impossible ; whilst a speed of 100 miles per hour upon land is not impossible, unless from undeniable imperfection in the structure of our lines. With a proper condition of permanent way, and with sufficient power, there would probably be no difficulty in maintaining a speed of 10,000 feet per minute at the peripheries of the driving wheels. A different construction of boiler, in which the steam would be generated in small tubes, and to a pressure of from 200 pounds to 300 pounds per square inch, would probably be requisite. The permanent way appears to be the principal matter in which radical improvement is necessary.”
RAILWAYS IN BRAZIL. Ten miles of railroad from the bay of Rio Janeiro to Petropolis have been in operation for several years, also 38 miles of the railroad from Rio Janeiro to Belem. The second section of the latter, which was let last year to American contractors, is rapidly progressing, with a force of 1,500 men, and it is confidently expected that it will be completed, according to contract, in May, 1863, and a considerable part of it a year or two sooner. When this section is finished the residue of the line, stretching in two branches along the Parahyba River, will soon be brought into operation, as the difficulties beyond the Serra, over which this second section passes, are not to be compared with those which Ameri. can skill and energy are now overcoming in the passage of the mountain.
A city railroad was constructed in Rio Janeiro last year, several miles long. towards Tejuca, a favorite summer resort, among the near mountains.