strong, according to the desired depth of yellow. At the end of two hours take them out, expose them to the air for half an hour, then wash them in a stream and wring them.

Prepare a bath, in which a sufficient quantity of neutral chromate of potash, (about from the fifteenth to the twenty-eighth part of the weight of the silk,) is dissolved. Neutralize the bath with half a glassful of hydrochloric, (muriatic,) acid. Leave your silks in it, during half an hour, at the mean temperature: twist or wring them over the liquor, and wash them in a slight solution of soap, just warm, then in a stream of cold water.

The shades of yellow are varied by altering the quantities of the mordant of sub-acetate of lead, and of the chromate of potash, which must always be deneutralized by hydrochloric acid.

Maryland Institute.

[Recueil Industriel.

We learn with great pleasure that our sister institution, the Maryland Institute, is in a prosperous condition, and pursuing with activity a course of great usefulness.

This society was founded in November, 1825. Its objects are the encouragement and promotion of manufactures, and the mechanic and useful arts, by the establishment of popular lectures upon the sciences connected with them; by the formation of a library and cabinet of models and minerals,-by awarding premiums for excellence in those branches of national industry deemed worthy of encouragement-by examining new inventions submitted for that purpose and by such other means as experience might suggest.

In January, 1826, a bill incorporating the Institute, passed both branches of the legislature of Maryland. In the course of the same year, several lectures were delivered by gentlemen, who volunteered their services for this purpose; an exhibition of the products of our mechanical industry was also announced.

The encouragement which was given to the new institution in its incipient state, justified the exertions that were made by the Board of Managers to place it immediately on such a footing of usefulness, as alone could impart to it stability and permanency. To produce this effect, no expenditure of time or money, consistent with the hopes which were justly created by the general interest manifested in behalf of the institute, was spared.

The Managers adopted measures to procure, as early as possible, an extensive apparatus, by means of which the lecturer could make all the necessary illustrations of the fundamental principles of mechanical and chemical philosophy. This having been obtained, the lectures, which had been partially suspended for want of the necessary apparatus, were resumed early last winter, and judging from the manner in which they were attended, appear to have given satisfaction.

Through the exertions of our worthy and efficient delegates, an

annual appropriation of three hundred dollars was made by the legislature. The lecture room has been so fitted up, as to afford comfort to the auditors, and enable the lecturer to carry on his demonstrations to the advantage of the respective classes.

Mr. Julius T. Ducatel has been appointed to lecture on natural philosophy and chemistry.

The number of subscribers to the society has increased, and the Managers and officers have, we learn, resolved to spare no exertions to secure to the public all the benefits originally contemplated on the foundation of the institution.

The following report will show the prosperous condition in which the Institute commences the operations of its sixth year of existence, and we wish every success to its laudable exertions.

Report of the Managers of the Maryland Institute.

The Board of Managers of the Maryland Institute for the promotion of the mechanic arts, deem it proper, at the commencement of another season of lectures, thus publicly to address the members, and the public generally, on the subject of the Institute committed to their charge. With varying success, this has continued from year to year, until it has become finally, and it is hoped permanently, established. Its object is by this time, too well known to need detailed explanation; it is sufficient to say, that, as its title purports, it aims, and has constantly done so, at the improvement of the mechanic and manufacturing arts, by placing the aids of the science connected with them, in the easy reach of their practisers and professors. Nor, is it believed, has it been altogether without useful attendant results.

The Maryland Institute, however, like many public establishments, lives on the health of public favour, with a better chance of continued existence perhaps, from the fact, that it does not call upon the charities of the community, but urges it on the score of its interests. To the members and to the public, the Board of Managers, therefore, now address themselves.

During the last winter, the chairs of chemistry and natural philosophy applied to the arts, were respectively filled, and full courses of lectures were delivered on these branches of science. The lecturers were the better enabled to effect this from the excellent accommodations in the Atheneum, and from the apparatus received from France, of a superior kind, and forming the chief part of an order, which, when it is all received, will make the apparatus of the Institute as full and complete as could be desired. The classes which attended the lectures were numerous, attentive, and composed of those who came to learn, and whose learning, when obtained, would be made of use and value, by their industry and intelligence. The drawing school under the direction of Mr. Smith, one of the ablest teachers in the country, and the secretary of the Board of

* Chronicle of the Times. Edited by J. T. Ducatel and G. H. Calvert.

Managers, was opened during the winter, under the auspices of the Institute.

Owing to the exertions of the delegation from this city in the legislature, this body appropriated the sum of three hundred dollars annually to the use of the Institute, so long as it shall be in efficient operation. This sum, though small, is satisfactory, both in the pecuniary assistance which it affords, and the interest which it evinces on the part of the state, in the success of the institution. Depending too for continuance upon the permanent efficiency of the Institute, it will act as a spur to the friends of the latter, to prevent the aid thus given, from being forfeited by neglect or inattention.

The Board of Managers, in making their arrangements for the ensuing season of lectures, deemed it expedient to unite the two chairs of chemistry and natural philosophy in one person, and ap pointed Professor Ducatel, of the University of Maryland, to take charge of them. With the talents and acquirements of this gentleman, the Board have every reason to be satisfied, and in their opinion on this subject, they are fully supported by the numerous audience which attended his lectures during the last winter. He will now lecture four times a week, twice on chemistry, and twice on natural philosophy. The Board have reason to believe that the remaining evenings of each week will be filled by occasional lectures from gentlemen of acknowledged ability, upon interesting subjects, so that the lecture room of the Institute, during the four winter months, will present a place of resort of the most agreeable and instructive character, where information and amusement may be readily and cheaply obtained. Mr. Smith will again open the drawing school, and when his own abilities, and the excellent collection of models of the Institute are considered, it is hoped that his class will be as numerous as the importance of the subject of his instruction ought to lead us to anticipate.

The contribution to entitle a person to the privilege of membership, is still three dollars, for which all the advantages of the Institute, except the drawing school, are obtained.

Connected with the Institute, is the Apprentices' Library, containing a numerous collection of works peculiarly adapted for the members of this Institution, and which the Board have now made arrangements to put in active circulation.

The Board of Managers confidently hope, that the Institution which has thus far existed, and added its portion of useful duty to the public, will still receive a general, liberal, and willing support. J. I. COHEN, Jr. Chairman.

On the Making of Charcoal.

THE subjoined notice has been going the rounds of the European and American Journals, without a single remark in either of them, respecting the author of the improvement to which it refers."

"Manufacture of Charcoal.-A new process, recommended in the

Journal des Forêts for this purpose, is to fill all the interstices in the heap of wood to be charred, with powdered charcoal. The product obtained is equal in every respect to cylinder charcoal; and independent of its quality, the quantity obtained is very much greater than that obtained in the ordinary method. The charcoal used to fill the interstices, is that left on the earth after a previous burning. The effect is produced by preventing much of the access of air which occurs in the ordinary method. The volume of charcoal is increased a tenth, and its weight a fifth."

The discoverer of the foregoing method of making charcoal, was Mr. Marcus Bull, of Philadelphia. The process was published in the Franklin Journal, for June, 1826, vol. i. first series, p. 358. By the following extract it will be seen that the foregoing account, from the Journal des Forêts, is given nearly in the words of the original publication.

"In the paper of Mr. Bull on the subject of fuel, that gentleman has described his method of obtaining charcoal, by surrounding the pieces of wood to be charred, with pulverized coal, by which a product is afforded equal in every respect to that made in cylinders, or retorts of iron. The Editor has seen some of the charcoal made upon this plan, in the large way; its superiority to that produced by the common process was very striking. The plan proposed can be pursued with facility and without expense, and the great saving of wood from the increased quantity obtained, is a circumstance which renders it of national importance."

Mr. Bull says, "it occurred to me that an important improvement might be made in the common process of making charcoal, by filling the interstices between the sticks of wood, with the culm, or fine coal, left on the ground after the large coal has been drawn from the pit; and by covering the wood more perfectly than is usually done. In this way we may more completely prevent the access of air, which is not only destructive, in many cases, to a large portion of the coal, but also renders what remains less valuable.”

"An intelligent collier in New Jersey applied, in a partial man-ner, the plan proposed. He found the product to be about 10 per cent. more in quantity, by measure, than he had ever before obtained from the same kind and quantity of wood; and I also found the coal when brought to market, nearly 20 per cent. heavier than usual."

Shell Lac and Seed Lac. Reply to Query.

[EDITOR

By turning to page 102 of the Franklin Journal, vol. ii. first series, the subject of seed lac and shell lac, as applied to varnishes, will be found to be treated at some length. The manufacturing of sealing The application of shell lac to the stiffening of hats, and various modes of bleaching this resin, have also been fully made known in this work. We wish that "Many Manufacturers" would purchase the volumes, and examine for themselves.

wax.

JOURNAL

OF THE

FRANKLIN INSTITUTE

OF THE

State of Pennsylvania,

DEVOTED TO THE

MECHANIC ARTS, MANUFACTURES, GENERAL SCIENCE,

AND THE RECORDING OF

AMERICAN AND OTHER PATENTED INVENTIONS.

FEBRUARY, 1831.

AMERICAN PATENTS.

LIST OF AMERICAN PATENTS WHICH ISSUED IN OCTOBER, 1830. With Remarks and Exemplifications, by the Editor.

(Concluded from page 16.)

91. For improvements in Machinery used in Steam Navigation; Franklin G. Smith, Lynchburg, Campbell county, Virginia, October 12.

Plates to accompany the specification of this patent are in the hands of the engraver.

92. For an improvement in the Mould or Instrument for Pressing Pine Apple Cheese; Myron Norton, Goshen, Litchfield county, Connecticut, October 13.

Instead of the netting usually employed to mark the lines upon pine apple cheese, moulds are to be made, of wood or metal, cast iron being preferred. Upon the insides of these moulds the requisite pattern is formed, by carving or otherwise. The moulds are made in three parts, and, when used, are confined together by proper bands. A tubular opening is left at the lower part of the mould, to fill it with curd, and into this a follower is fitted for the purpose of making pressure.

The claim is to "the substitution of the mould of metal, or wood, carved, or cast in manner and form described; and the manner or principle of giving the stamp or impression in the cheese by said VOL. VII.-No. 2.-FEBRUARY, 1831.

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