It is necessary that this Office should possess information on these points, the law clearly requiring, though not in express terms, that descriptions of all known inventions should be within reach, that patents may not be granted for things previously secured. Irrespective of the light they will reflect on the origin of inventions to which they relate, and early struggles of inventors, an increasing interest will be attached to them as matters of enlightened curiosity.

Information respecting the forms of patents, léngth of time for which they were granted, fees paid, &c., will be highly acceptable, as also anything relating to the early progress of the arts in your State.

In case no official documents of the kind are on file, may I beg the favor of your referring the subject to any literary or scientific society, or to private individuals who may be in possession of the information sought.

With sentiments of high regard, I have the honor to be your obedient servant,

His Excellency

THOMAS EWBANK, Commissioner. Governor of

[NOTE. It is not known that patents were issued for inventions in Louisiana by the French, or in Florida, Texas, and New Mexico by the Spaniards; but if any were granted, copies of them would be of unusual interest]

[B.]

UNITED STATES PATENT OFFICE.

SIR: A copy of the accompanying Circular has been addressed to each of the governors of the States and Territories of the Union, and I respectfully solicit your co-operation in furthering the objects sought to be accomplished. Whatever assistance or advice your more important engagements may permit you to give, will be highly appreciated.

There are, it is believed, among your constituents, descendants of old inventors and patentees, who, having documents of the kind referred to in their possession, would be glad to have them filed in this Office, and noticed in its Reports, as an act of justice to the ingenuity and memories of their ancestors.

I have the honor to be, with sentiments of high regard, your obedient

servant,

Hon

THOMAS EWBANK.

IX.

COMMUNICATIONS.

1. ON CHINESE HOROLOGY, WITH SUGGESTIONS ON THE FORM OF CLOCKS ADAPTED FOR THE CHINESE MARKET.

2. ON THE TALLOW-TREE OF CHINA. [See the Agricultural portion of the Report.]

NINGPO, August 29, 1851.

MY DEAR SIR: As the object of the accompanying papers is of a public character, and as they were drawn up in accordance, it is believed, with the wishes of the Department over which you preside, I trust I shall not be considered trespassing in forwarding them overland, particularly as I can avail myself of no other safe channel. I have already forwarded, via the Cape, per ship, sundry seeds, eggs of the silk-worm, with specimens of vegetable tallow and insect wax, which will be anticipated doubtless in their arrival by this. The paper on the Tallow tree may be useful to southern agriculturists, as the same, or a kindred species, is common in that section of our country. I hope, also, that I have not taken too much liberty in sending a duplicate of my paper on Clocks, under cover to your Department, for Silliman's Journal.

I cannot conclude this note without expressing my personal regard for you as a townsman and acquaintance. I knew you well in my boyhood as one of the fathers and patrons of the New York Mechanics' Institute, with which I was early connected; again I became acquainted with you as an author, (but, alas! I have not your work in my library;) and now, in my voluntary exile, I meet you as it were, after the lapse of many years, as the director of an important institution of my native land. Will you not suffer the acquaintance to be continued so far as to favor me with copies of all public documents of scientific interest which you may have at your disposal.

Be so good as to let me know if I can serve you in any way in China, and believe me, my dear sir, yours, most faithfully, D. J. MACGOWAN.

THOS. EWBANK, Esq.,

Commissioner of Patents.

On Chinese Horology, with suggestions on the form of Clocks adapted for the Chinese market.-Written for the Patent Office Report, by D. J. Macgowan, M. D., of Ningpo, China.

A request made about two years since by the United States Patent Office, for information from American citizens resident in China, calcu

lated to be useful to home industry, has not received that attention which it merits, notwithstanding there exist as incentives, on the one hand, the unrenounceable claim of country, and, on the other, the ample opportunities for complying with that request. Her wide-spread territory, the varied productions of her soil, and the high position of China as an agricultural State, lead us to expect that no inconsiderable addition to our own agriculture would result from a careful survey of the various points accessible to foreigners; and it would doubtless be found that many plants, indigenous to this soil, are capable of being naturalized in one part or another of our continent.

In a manufacturing point of view, although there is much less to repay research, yet there are some branches of industry in this department the investigation of which could not fail to bring valuable facts to light; and, if no more can be done than to point out defects in Chinese labor, which our artisans can supply, that alone would prove mutually advantageous to the two great nations on the opposite shores of the Pacific.

Clock-making, which forms the subject of this note, is a case in point; and it is believed that, with a modification to be suggested, American clocks can be made an article of extensive import into China. For a long period the importation of clocks and watches, chiefly the former, into this country from the continent of Europe, was little short of half a million of dollars annually. This trade has nearly ceased, partly owing, no doubt, to the rapid impoverishment of the country by the opium traffic, and partly to the fact that native manufacturers are able to compete with foreigners. Yet clocks are not often met with in China; they are generally confined to the public offices, where it is common to find half a dozen all in a row. The number annually manufactured cannot be large, for in the richest cities of China clock-makers are not numerous. At Nankin there are 40 shops; at Suchau, 30; Hangchau, 17; and at Ningpo, 7; the average number of men employed in each being less than four, who are mostly occupied in repairing watches and clocks. The cheapest clock they make costs $7. Some are worth as much as $100— the most common price being about $25 each. A manufacturer estimates the number of clocks made at the above places at 1,000 per annun; and probably 500 more would more than cover the whole annual manufacture of the empire. A few watches are made, with the exception of chain and spring, which are imported. The oil used by Chinese workmen to abate friction appears to be particularly adapted for that purpose, though expensive; it is obtained from the flowers of the Olea Fragrans.

Before describing the kind of clock which seems adapted for this market, a brief glance at the history of the horological art in China may not be inappropriate. It had its rise, as in the western side of Asia, in the clepsydra.

Assuming-what is in the highest degree probable-the authenticity and accuracy of the Shuking, we find that, forty-five centuries ago, the

* CHRONOLOGY.-Although doubts may exist respecting the absolute accuracy of Chinese chronology, it must, nevertheless, be admitted that it is so far correct as to render arguments founded on the commonly-received chronology altogether untenable; and it is matter of regret, therefore, that the latter has been followed, in their Chinese publications, by all Romish and Protestant missionaries I cannot too earnestly urge the adoption of Hale's Chronology, and that speedily, lest, in the mean time, some Chine e Celsus or Porphyry should arise, and bring objections against our faith not easily answered to the satisfaction of their countrymen.

Chinese had occupied themselves with the construction of astronomical instruments somewhat similar to the quadrant and arinillary sphere, and the observations they made with them, even at that remote period, are remarkable for their accuracy, enabling them to form a useful calendar. The present cycle of sixty was adopted at that time, by Hwangti, (2697-2597 B. C.) To this emperor is attributed the invention of the clepsydra. The instrument at that period was probably very rude, and not used as a time-piece, but for astronomical purposes, in the same manner as employed by Tycho Brahe, for measuring the motion of stars, and subsequently by Dudber in making maritime observations. It was committed to the care of an officer of rank styled clepsydra adjustor.

The greatest philosopher in Chinese history anterior to Confucius was Duke Chau, the alleged inventor of the compass. He appears, also, to have been the first to employ the clepsydra as a time-piece. He divided the floating index into one hundred equal parts, or "kih." In winter, forty kih were allotted to the day, and sixty to the night, and in summer this was reversed. Spring and autumn were equally divided. This instrument was provided with forty eight indices, two for each of the twenty-four terms of the year. They were consequently changed semi-monthly-one index being employed for the day and another for the night. Two were employed every day, probably, to remedy in a measure the obvious defects of all clepsydras-of varying in the speed of their rise or fall, according to the ever-varying quantity of water in the vessel, which might be done by having the indices differently divided. To keep the water from freezing in winter, the instrument was connected with a furnace, and surrounded by heated water. Chau flourished eleven centuries before our era. The forms of the apparatus have been various, but they generally consisted of an upper and a lower vessel, always of copper, the former having an aperture in the bottom, through which water percolated into the latter, where floated an index, the gradual rise of which indicated successive periods of time. In some this was reversed, the float being made to mark time by its fall. A portable one was occasionally employed, in ancient times, on horseback, in military tactics. Instruments constructed on the same principles with the above were in use among the Chaldeans and Egyptians at an early period-that of Ctesibius, of Alexandria, being an improvement over those of more ancient times. The invention of Western Asia was doubtless wholly independent of that of the East, both being the result of similar wants. Clepsydras were subsequently formed of a succession of vessels communicating by tubes passing through dragons, birds, &c., which were rendered still more ornamental by the indices being held in the hands of genii.*

The earliest application of motion to the clepsydra appears to have been in the reign of Shuenti, (126-145 A. D.,) by Tsianghung, who constructed a sort of orrery representing the apparent motion of the heavenly bodies around the earth, which was kept in motion by dropping water. There is reference, also, to an instrument of this description in the third century.

The accompanying drawings of two of the numerous forms of the instrument are from an old astronomical work, where they are found without any description.

In the sixth century, an instrument was in use which indicated the course of time by the weight of water, as it gradually came from the beak of a bird and was received into a vessel on a balance, every pound representing a kih. About this time mercury began to be employed, instead of water, which rendered the aid of heat in winter unnecessary. Changes were made also in the relative number of kih for day and night, so as to vary with the seasons.

As in Europe, monks of the Roman church devoted considerable attention to mechanical inventions, especially in the construction of instruments for measuring time for the regulation of their worship and vigils; in like manner, also, Buddhist monks, in their silent retreats, but at an earlier period, similarly occupied themselves, and for the same purposes. Several instruments, designed as time-pieces, the invention of priests, are mentioned in Chinese history. They present nothing novel, however, with the exception of one, which is nothing more than a perforated copper vessel, placed in a tube of water, which gradually filled and sunk every hour, requiring, of course, frequent attention. Although their knowledge of hydrodynamics has ever been very limited, the Chinese appear to have been the first to devise that form of clepsydra to which the term water-clock is alone properly applied; that is to say, composed of apparatus which rendered watching unnecessary by striking the hours. Until the commencement of the eighth century, the persons em. ployed to watch the clepsydra in palaces and public places struck bells or drums every kih; but at this period a clock was constructed, cousisting of four vessels, with machinery which caused a drum to be struck by day, and a bell by night, to indicate the hours and watches. No description of the works of this interesting invention can be found. It is possible, however, that the Saracens may have anticipated them in this invention of water clocks.

In the history of the Tong dynasty, (620-907,) it is stated that in the Fahlin country, (which, in this instance, doubtlessly means Persia, though the best living authority amongst the Chinese makes it Judea,) there was a clepsydra on a terrace near the palace, formed of a balance, which contained twelve metallic or golden balls, one of which fell every hour on a bell, and thus struck the hours correctly. It is not improbable that this instrument is identical with the celebrated one which the king of Persia sent, in 807, to Charlemagne.

In 980 an astronomer, named Tsiang, made an improvement on all former instruments, and which, considering the period, was a remarkable specimen of art. The machine, which was in a sort of miniature terrace, was ten feet high. divided into three stories, the work being in the middle. Twelve images of men, one for every hour, appeared in turn be fore an opening in the terrace; another set of automata struck the twelve hours, and the kih, or eighths, of such hours. These figures occupied the lower story; the upper was devoted to astronomy, where there was an orrery in motion, which, it is obvious, must have rendered complex machinery necessary. We are only told that it had oblique, perpendicular, and horizontal wheels, and that it was kept in motion by falling water. As the Saracens had reached China by sea at the close of the eighth century, and by land at an earlier period, some assistance may have been derived from them in the construction of this instrument; but I am disposed to consider it wholly Chinese. Beckman, after much learned research, ascribes the invention of clocks to the Saracens, and the first