and there were other objections to it, too. The ruby was then tried, as being the next hardest jewel. A nib could be made of this, but it was not without objections, and was not considered to be hard enough. Dr. Wallaston," says the Tribune, "had sent to a ruby pen manufacturer, in London, sundry specimens of rhodium, and the native alloy of iridium and osmium, minerals found in combination with platinum, with a request that a pen might be formed from each. Accordingly a few were made, but from the rhodium alone, the iridium being returned to Dr. W. by the manufacturer, with the remark that it was too hard to be worked into figure."

Here now was a starting point for Mr. Hawkins, from which to reach that point so desiderated by him, an indestructible nib, in the pursuit of which he had expended much time, capital and labor. He commenced making experiments on iridium, and satisfied himself that, as regarded hardness, it was just the thing he wanted. It was found to be much harder than ruby, for, being exposed to the action of diamond powder, rotating in a lathe at the rate of five thousand feet per minute, it "was slightly abraded in five minutes," and a ruby, submitted to the same test, was worn away to the same extent in one-third of the time. The next thing to be done, and the most difficult, was to form the nib of this material, and to fix it permanently to the point of the gold pen, which Mr. Hawkins, after much experiment and labor, succeeded in doing. This was about the year 1834, and thus begins (says the Tribune) the actual history of the gold

pen as such."

Iridium is the third heaviest metal, or mineral, so far known, we believe, being the next heaviest to gold, which is next to platinum. It is not malleable, and is worked with very considerable difficulty. It is soluble iu muriatic acid, and takes its name from the variety of colors it assumes when undergoing the process of solution-iris being the Greek word for rainbow. hence iridium. It is found in Siberia and South America, not in great quantities, however, and is costly, the price varying from thirty to seventy-five dollars the ounce, and it has been sold as high as one hundred. In preparing it for pen points the waste is very great, not being less than seven-eighths, as it comes into the market. As yet, no meaus have been found of making the refuse, in any way, available, and, as it is not malleable nor fusible, but by the application of intense heat, as of the voltaic battery, it is questionable if this will ever be done.

The Tribune enumerates eighteen processes and manipulations, as belonging to the manufacture of the so-called gold pen, the first of which is the melting of the gold, the last the proving of the pen, when finished, by writing with it. The sixth process is the soldering of the nib to the gold part of the pen, which is done by the application of a "minute jet of flame," which supplies an intense

heat.

It is stated that there are now, in the United States, about twenty establishments, more or less extensive, for the manufacture of gold pens. In the State of New York there are not less than a dozen, five or six of them being in the city, and in active operation. Some manufacturers melt gold three times a week. In one establishment they use about one thousand dollars per week. "Victoria sovereigns are generally used in preference to all other qualities of gold;" why, the Tribune does not say, nor do we, not knowing. Fine gold jewelry is used, too, and yet the metal for the pen is reduced by alloys of silver and copper to twelve, fourteen, or sixteen carats, which are but so many parts out of twentyfour-the number representing pure gold.

There are two factories, making but one establishment, one in New York, the other in Boston, that turn out one hundred and four thousand gold pens annually between them. It is supposed that about two hundred ounces of iridium are consumed, annually, for the pens manufactured in this country, though not more than thirty, probably, are actually used in the shape of pen points. Of course the point must be extremely minute; and yet, Mr. Hawkins says, "with fair usage, it is a pen for life." Let us Be moderate, and suppose for a few years. That even is achieving much, as all will know, who have had experience, as regards the continual making, mending, splitting and spoiling, of the ancient, venerable, and still ever-to-be-held-in-respectful-remembrance, 66 gray goose

quill."

When gold pens,were first introduced into London they sold at £1 ($4 80) each, without a holder. In New York the regular price is $2 50, with silver holders, though they may be had, sometimes, at auction for much less. Mr.

Hawkins says the American manufacturers are ahead of the English, as regards ingenuity, which is evident from their inventing, "labor-saving tools and ready methods of working; while the sluggish and let-well-alone feeling of the Eng. lish workmen, in my employ, formed a clog to the introduction of new tools and methods of working into my manufactory, even when plainly indicated by experience."

This, we have no doubt, is all true, and we think it quite likely that American pen manufacturers can purchase British gold, make it into pens, take them to London and undersell the London manufacturer, supposing them to be introduced free of import duty; which would not be the case, however, for English free trade principles have not yet got so far as to include gold pens.

DEPARTMENT OF INTERNAL IMPROVEMENTS.

1. ADVANTAGES OF PLANKROADS OVER RAILROADS. 1. Plankroads are more easily and cheaply constructed than railroads. 2. They are more easily kept in repair, and yield a larger and more certain return to the stockholders.

3. Produce can be carried over them at least twenty-five per cent. cheaper than on railroads.

4. They are particularly adapted to the southern States, because of the abundance of timber here, and the character of the power used.

5. They accommodate a larger number of people, because they can be carried almost to every man's door, while railroads cannot.

6. They tend to sustain a local population, and build up a home market in every neighborhood which they penetrate.

To these I may add that plank roads are better adapted to an agricultural country, because they can be constructed and kept in repair by the planters themselves; and, because the planters can own them and manage them so as to make the transient travel pay the expense of earrying their own cotton to mar ket, and also return a handsome interest besides.

I know, Messrs. Editors, that many of your country readers particularly, look upon every man who advocates the construction of plankroads as a brainless visionary. They contend

1. That the timber will decay so soon in this climate, that the road will be rendered worthless in the few years at most.

2. That the roads will be so narrow as to be perfectly useless for all practical purposes, especially where we have negro drivers.

3. That the planters will not travel upon them in consequence of the tolls charged; but give preference to the common roads.

4. That the country is not sufficiently densely populated to furnish either trade or travel enough to sustain them.

I will answer these objections in order.

1. It will take no more timber to build a plank road than to lay the superstructure of a railroad, and it will last at least one-third longer upon the former than upon the latter. The objection in regard to the decay of timber, therefore, is much stronger against the railroad than against plankroads. The weight is so immense, that to render the former safe for heavily laden cars, timbers have often to be thrown away before they are half decayed. This would not be the case with plankroads. In the northern States the planks used are of hemlocka soft, sappy wood-and yet they last some ten or twelve years. It is but fair to conclude that yellow pine will last as long at the South as the hemlock will at the North. If this be conceded, the question is settled, because, even in the least densely settled sections of New York these roads are paying from 25 to 40 per cent. upon the cost of their construction, after laying up a reserved fund sufficient to rebuild them every ten years.

2. If eight feet be found to be too narrow for these roads at the South, it will be an easy matter, in consequence of the abundance of timber and the levelness

of the country, to increase the width to twelve, or even sixteen feet, and still to restrict their cost within the sum paid for their construction at the North. Eight feet at the North, where the population is much more dense, is found to be quite ample. The road is so well graded, so well drained, and kept in such thorough order, that wagons can turn out at any point with perfect convenience. 3. That planters will not pay the tolls to enjoy the benefits of these roads, no sane man can believe. Let us suppose a road constructed from Macon to Talbotton, say sixty-five miles in length. It now requires a six-horse team nearly four days to haul eight bales of cotton from Talbotton to Macon. At $5 per day, the cost of delivering these eight bales would be $20. By a plank road the same team would deliver twenty bales in two days, or at a cost of $10. In one case the hauling costs $2 50 per bale; in the other only fifty cents per bale. It is plain that the planter or wagoner could afford to pay $1 per bale toll, and then save $1 per bale in addition to the saving in wear and tear of wagons and horses. Nothing is plainer than that men pursue their interest, and planters are just as quick to discover their interest as any other class of men. A road to Talbotton would concentrate at that point 20,000 bales of cotton, and a branch from it to the Waymanville factory would concentrate there 12,000 to 15,000 bales more. Can any man doubt that the planters would not gladly pay the tolls and use the road in preference to the common roads of the country? I think not.

4. The idea that the country is not densely enough populated to sustain such a road is equally incorrect. The roads themselves will soon supply the necessary density of population. This has been pre-eminently the case with railroads and canals. The increased value of property along the Erie canal, was more than sufficient to pay for its construction, and this increase was occasioned by the demand brought about by the influx of population.

2. PLANKROADS.

The following, taken from a recent report of O. G. Gates, Secretary of the Kentucky Board of Improvements, contains valuable and interesting information to those interested in road improvements:

1. The system of plankroads which originated in Russia, has since been adopted in Canada, and in many of our northern States entirely superceded the McAdam and Telford rock or gravel roads. The great success and value of the plank road consists in the cheapness, in ease of draft, in speed, and in comfort to passengers.

2. The approved mode of construction thereof, is as follows: For a single track the planks (of pine, hemlock, oak, red elm, black walnut or sweet gum) should be eight feet long, and from three to four inches thick; they should be laid across the road at right-angles to its line. These planks are to rest on two longitudinal sills or sleepers, each four inches square, bedded in the earth to their full thickness. The earth should be fully kept up to the planks at every point, in order to prevent confined air resting in any vacant space beneath the planks-no pin or spike is needed to confine the plank to the sleepers, their weight being sufficient to keep them firm. There should be placed on the upper surface, a coating of sand an inch thick. There should be provided for a single track, turn-out places-and to effect this, an earthern road must be banked up ten or twelve feet wide on one side, and two or three on the other; each embankment should be made flush with the ends of the plank, and thence sloping outward so as to carry off the water, as perfect drainage is the great secret in the construction of any kind of road. The plank should be laid even, with part thereof projecting two or three inches beyond the general line of the road, in order to prevent ruts made by wheels at the junction of the plank and each turn out. And if the bed on which the planks are to be laid is a new one, it would be better to be traveled one season before they are laid down. One track, with the supplementary earth road thus formed, will be sufficient for all ordinary travel. And, if the tonnage transported on the road be chiefly in one direction, the track should be laid on that side of the road which will enable the loaded teams to keep it, and thereby force the unloaded ones to do all the turning out.

3. To make a double track, all that is needed, will be to make two tracks each eight feet wide, or one sixteen feet wide. The former is preferred. For

the sixteen feet track, three or five longitudinal sills are required, each to be four by six inches, and laid edgewise and embedded in trenches six inches deep. These timbers should be from fifteen to twenty feet long. Great advantage is obtained in the construction of the double track with long plank, by giving the road bed a slight convexity of two or three inches in the center, and springing the plank down to the outside sills, and attaching them thereto by half inch spikes or nails three inches long.

4. The duration of plankroads is from eight to twelve years; this matter, however, depends entirely upon decay from rot, and not by the surface wear of the plank. The sand which is spread upon the track when finished, protects the wood from the shoe soles of the horses (which cause most of the wear), and soon penetrates the grain of the plank, until, with the woody fibers and the deposits on the road, a tough elastic covering is formed, whereby the plank is saved from the further wear. Experience teaches that one-half the wear and tear of seven years occurs in the first year. Therefore, it is a matter of great importance on these roads to have small tollage, in order to invite such an amount of travel as will promote their wearing out instead of rotting.

5. The cost of the plankroad greatly depends on its locality. But it will be found the following estimate will approximate to an average valuation, to wit: For one mile of road with a single track (made with plank eight feet wide and three inches thick), will require 126,720 feet board measure of plank, and of sills 4 by 4, 14,080, making in all of lumber 140,800 feet, and costing say five dollars per thousand, would equal the sum of seven hundred and four dollars. The laying and grading will cost from 30 cents to a dollar per rod, or from ninety-six dollars to three hundred and twenty dollars per mile. The earth work, sluices, bridges and contingencies, admit of no average estimate. Therefore, without them, and one hundred dollars per mile for engineering su perintendence, and one hundred dollars for gate houses, we have the total cost per mile from one thousand to one thousand two hundred and twenty-four dollars.

DEPARTMENT OF COMMERCE.

1. THE WABASH VALLEY-ITS OUTLETS AND INLETS. No sane man, that we have heard, disputes the fact that the Wabash valley is one of the most fertile and inexhaustible agricultural districts in the United States. This has always been its general reputation with special verifications whenever an observing and intelligent stranger has visited that region. And no one can ever have been engaged in business at New Orleans, or as a trader between that city and the shipping points on the Ohio river, without hearing of the Waba h ghut-an outpouring of western produce from that rich valley, with the early spring freshets, which made it necessary for persons engaged in the purchase and sale of the various articles embraced, to “stand from under" the load that the hoosiers were heaping upon their shoulders.

But of late years, the inhabitants of the Wabash valley have shown a strong inclination to go extensively into manufacturing operations-for that term is applied, in commercial parlance, to the putting up of pork and the kegging of lard-and now the pork prices of Porkopolis itself are bearded in their very dens, at New Orleans, by the hoosiers, who have added to the usual articles heretofore making up the celebrated "Wabash glut," barrel and bulk pork, lard, flour, &c.

But even this does not seem to satisfy our friends of the Wabash valley. Among our advertisements to-day, may be found a notice of Water Power to Let," by the Wabash Navigation Company at Vincennes. This power amounts to a propelling force sufficient for 400 run of 41% feet stones, and may be applied on either side of the river. Vincennes is a point at which grain can be very conveniently delivered, and no one can doubt, that out of the mouth of the Wabash will hereafter go heavy and constant shipments of flour and meal.

The works erected at Vincennes, by the Wabash Navigation Company, are one of the most important improvements yet made on any of the rivers of the West. Before the erection of the dam and lock at the rapids, the Wabash was navigable by only a very small class of boats, and for only a few months each year. Since the completion of that improvement, boats of good size have been able to pass the rapids, e cry month in the year, and a direct and regular trade has been successfully opened with New Orleans, Cincinnati, Pittsburg and other important points. With reference to this improvement, an Indiana correspondent communicated a number of very interesting facts some weeks ago, for which we are under obligations to him. His communication was inadvertently lost sight of soon after its reception, but is not the less interesting now than it would have been if published then. He says:

"The Wabash Navigation Company was chartered by Indiana and Illinois in the winter of 1846 and 1847; preparations for the work were made in the fall of 1847, and it was intended that it should be completed in the fall of 1848. The lock was completed, and the dam was nearly finished, when all work was stopped by the flood, and a part of the dam was washed away; in the fall of 1849 the work was resumed, and the dam was completed about the first day of November last. The lock is the largest in the world-being sufficient to pass a boat 50 feet in width and 230 feet in length; a little longer and considerably wider than the Louisville lock. The stock of the Company is mostly owned at Vincennes. In consequence of the partial destruction of the dam in 1849, at certain stages of the water, steamboats and flatboats could and did safely pass through the dam. But the dam as it was did increase the water on the rapids; and hence at certain other states of the water the lock was used; and hence, too, there was an increased steamboat navigation on the river in 1849. Steambats pas ed the lock at the rapids of the Wabash in each month of the year 1849. The following statement is taken from the reports of the collector of tolls, on file with John Ross, Esq., secretary of the company. The steamboat passages through the lock in each month of 1849 were as follows: January, 8; February, 11; March, 35; April, 35; May, 26; June, 4; July, 2; August, 4; September, 2; October, 4; November, 3; December, 36-total 152 passages, or 76 steamboat trips up and down, proved by the tolls paid. How inany passed through the breach in the dam is not known, but probably as many more. The following is a continuation of the above statement to the last report. January, 1850, 51; February to the 22d, 45; total 96 passages. And the following is a statement of the whole business for the present season: November, 3; December, 36; January, 51; February to the 22d, 45; total 135 passages. The writer has himself seen, lately, the following boats in the Wabash with full cargoes loaded for or at New Orleans: Tribune, Globe, Dove, North Carolina and Warrior. On the evening of the 20th February, there were three boats at the Vincennes landing; one from New Orleans, one from Cincinnati, and one from Lafayette; at the stage of water at that time, but for the dam, there would not have been more than three feet six inches on the rapids. It is well known here, that Vincennes packed pork, shipped by steamboat to New Orleans, was on sale at Boston on the last of February-and from the reports above mentioned, it appears that toll has been paid this season on 4,115,131 lbs. of bulk pork, and on 36,647 barrels of pork: less than half the quantity packed on the river."

A report made some time since the statement of our correspondent came into our possession, shows the business of the Wabash improvement for the period of five months-commencing on the first of December last, and ending on the first of May instant. The total number of steamboats that passed the lock within this period, was 245; the total number of flatboats, 140. The number of passengers moving up and down during this time, is stated at 2,650.

Among the articles of freight passed through the lock during the period of five months above specified, were 50,735 barrels of pork, 7,666,578 fbs. bulk pork and bacon, 1,994,645 lbs. lard, 1,483 live hogs. 129 cattle, 1.974 dozen poultry, 325,794 bushels of corn, 1,000 bushels wheat, 55,092 bushels oats, 1,484 bushels rye, 82 bushels barley, 18,613 barrels salt, 6,278 sacks salt, 1,290 barrels whisky, 3,065 barrels molasses, 7,339 barrels flour, 161 barrels apples, 2,852 bushels potatoes, 319 barrels lime, 93% tons of hay, 145,338 feet lumber, 20,000 staves, 21,185 hoop poles, 8,574,081 ibs. merchandise, groceries, &c.

The descent of the Wabash at Vincennes, is about 9 feet within a distance of