cross-bow, for taking altitudes of the sun and stars, with some contrivance for the more ready collecting the altitude from the observation. The discoveries concerning the logarithms were carried to France in 1624, by Edmund Wingate, who published two small tracts in that year at Paris. In one of these he taught the use of Gunter's scale; and in the other, of the tables of artificial sines and tangents, as modelled to Napier's last form, erroneously attributed by Wingate to Briggs.

Gunter's ruler was projected into a circular arch by the Rev. William Oughtred in 1633, and its uses fully shown in a pamphlet entitled, "The circles of Proportion;" where, in an appendix, are well handled several important points in navigation. It has also been made in the form of a sliding ruler.

The logarithmic tables were first applied to the different cases of sailing by Thomas Addison, in his treatise entitled, "Arithmetical Navigation, printed in 1625, in which he gives two traverse tables, with their uses; the one to quarter points of the compass, the other to degrees.

Henry Gellibrand published in 1635, his discovery of the changes of the variation of the compass, in a small quarto pamphlet, entitled, "A Discourse Mathematical, on the Variation of the Magnetical Needle." This extraordinary phenomenon he found out by comparing the observations made at different times, near the same place, by Mr. Burrough, Mr. Gunter, and himself-all persons of great skill and experience in these matters. This discovery was soon known abroad; for F. Athanasius Kircher, in his treatise entitled "Magnes," first printed at Rome, in 1641, informs us, that he had been told it by John Greaves; and then gives a letter of the famous Marinus Mersennus, containing a very distinct account of it.

As altitudes of the sun are taken at sea, by observing his elevation, or altitude, above the visible horizon, to obtain from thence the sun's true altitude with correctness, Wright thought it necessary, that the dip of the horizon below the observer's eye, should be brought into account, which cannot be calculated without knowing the magnitude of the earth. Hence he was induced to propose the different methods for finding this; but complains that the most effectual was not in his power to execute; and, therefore, contented himself with a rude attempt, in some measure sufficient for his purpose. dimensions of the earth, deduced by him, corresponded so well with the usual divisions of the log line, that as he did not write an express treatise on navigation, but only for correcting such errors as prevailed in general practice, the log line did not come under his notice.

The

Mr. Richard Norwood, however, put in execution the method recommended by Mr. Wright as the most perfect for measuring the magnitude of the earth, with the true length of the degrees of a great circle upon it; and, in 1635, he actually measured the distance between London and York: from which, and the summer solstitial altitudes of the sun, observed on the meridian at both places, he found a degree, on a great circle of the earth, to contain 367,196 English feet, equal to 57,300 French fathoms or toises; which is very exact. as appears from many measures that have been made since that time. Mr. Norwood gave a full account of this, in his treatise, called the Seaman's Practice, published in 1637, in which he shows the reason why Snell had failed in his attempt. He also points out the various uses of his discovery, particularly for correcting the errors hitherto committed in the divisions of the log line. These necessary amendments, however, were little attended to by navigators, whose obstinacy, in adhering to established errors,

has been complained of by the best writers on navigation; but, at length, they found their way into practice, and few navigators of reputation now use the old measure of forty-two feet to a knot. In that treatise, Mr. Norwood also describes his own excellent method of setting down and perfecting a sea reckoning, by using a traverse table; which method he had followed, and taught for many years. He also shows how to rectify the course by the variation of the compass; also, how to discover currents, and to make proper allowance for them. This treatise, and one on trigonometry, were frequently reprinted, as the principal books used in teaching scientifically the art of navigation.

No alterations were made in the Seaman's Practice till the twelfth edition, in 1676, when the following paragraph was inserted in a smaller character: "About 1762, M. Picart published an account in French, concerning the measure of the earth, a brief account of which may be seen in the Philos. Trans. No. 112; wherein he concludes one degree to contain 365,184 English feet, nearly agreeing with Mr. Norwood's experiment;" and this advertisement is continued, in the subsequent editions, as late as 1732. About 1645, Mr. Bond published, in Norwood's Epitome, a very great improvement in Wright's method, by a property in his meridian line, whereby its divisions are more scientifically assigned than the author himself was able to effect; which was from this theorem, that these divisions are analogous to the excesses of the logarithmic tangents of half the respective latitudes, augmented by 45° above the logarithm of the radius. This he afterwards explained more fully, in the edition of Gunter's works, printed in 1653; where, after observing that the logarithmic tangents, from 45° upwards, increase in the same manner that the secants added together do, if every half degree be accounted as a whole degree of Mercator's meridional line; his rule for computing the meridional parts belonging to any two latitudes, supposed on the same side of the equator, is as follows: "Take the logarithmic tangent, rejecting the radius of half each latitude, augmented by 45°; divide the difference of those numbers by the logarithmic tangent of 5° 30', the radius being likewise rejected; and the quotient will be the meridional parts required, expressed in degrees." This rule is the immediate consequence of the general theorem, that the degrees of latitude bear to one degree (or 60 minutes, which in Wright's table stand for the meridional parts of one degree) the same proportion as the logarithmic tangent of half any latitude augmented by 45°, and the radius neglected to the like tangent of half a degree, augmented by 45°, with the radius also rejected.

The demonstration of this general theorem was still wanting, till supplied by Mr. James Gregory, of Aberdeen, in his Exercitationes Geometricæ, printed at London, in 1668; and afterwards more concisely demonstrated, together with a scientific determination of the divisor, by Dr. Halley, in the Philos. Trans. for 1695, from the consideration of the spirals into which the rhombs are transformed, in the stereographic projection of the sphere upon the plane of the equinoctial; and which is rendered still more simple by Mr. Roger Cotes, in his Logometeria, first published in the Philos. Trans. for 1714. It is added in Gunter's book, that if one twentieth of this division, which does not sensibly differ from the logarithmic tangent of 45° 1' 30" less radius, be used, the quotient will exhibit the meridional parts expressed in leagues; and this is the divisor mentioned in Norwood's Epitome. In the same manner the meridional parts will be found in minutes, if the same logarithmic tangent of 45° 1' 30" less radius be taken, that is, the number used

by others being 12,633, when the logarithmic tables consist of eight places of figures.

Mr. Bond, in his Seaman's Kalendar, declared that he had discovered the longitude by having found out the true theory of the magnetic variation; and to gain credit for his assertion, he foretold, that in London, in 1657, there would be no variation of the compass, and from that time it would gradually increase the other way; which happened accordingly. He also published a table of the variation, in the Philos. Trans., for forty-nine years to come. He thus acquired such reputation, that his treatise, entitled, The Longitude Found, was published in 1676, by the special command of Charles II., and approved by many celebrated mathematicians.

It was not long. however, before it met with opposition; and, in 1678, another treatise, entitled, The Longitude not Found, made its appearence; and as Mr. Bond's hypothesis did not, in any manner, answer the author's sanguine expectations, the affair was undertaken by Dr. Halley. The result of his speculations was, that the magnetic needle is influenced by four poles; but this wonderful phenomenon seems, hitherto, to have eluded all our researches. In 1700, Dr. Halley published a general map, with curve lines expressing the paths where the magnetic needle had the same variation; which was received with universal applause. But as the positions of these curves vary, from time to time, they should frequently be corrected by skilful persons; which was accordingly done in 1744 and 1756, by Mr. William Mountaine and Mr. James Dodson, F. R. S.

After the true principles of the art were settled by Wright, Bond. and Norwood, the authors on navigation became so numerous, that it would be a difficult matter to enumerate them; and every thing relative to it was settled with an accuracy, not only unknown to former ages, but which would have been reckoned utterly impossible. The earth being found to be a spheroid, and not a perfect sphere, with the shortest diameter passing through the poles, a tract was published in 1741, by the Rev. Dr. Patrick Murdoch, wherein he accommodated Wright's sailing to such a figure: and Mr. Colin McLaurin, the same year, in the Philos. Trans. gave a rule for determining the meridional parts of a spheriod; which is treated of more fully in his treatise of Fluxions, printed at Edinburgh in 1742.

Among the later discoveries in this science, that of finding the longitude at sea, by Lunar Observations, and by Time-keepers, is the principal. The science is indebted to Dr. Maskelyne for putting the first of these methods into practice, as well as for many other improvements; and also to Mr. Harrison for the remarkable discovery of the longitude by the second method. The subject of nautical science has been so much canvassed and studied, by men of learning and ingenuity, in all nations, that there seems to be little room for further improvements; and the art of navigation appears to be nearly brought to the greatest degree of perfection of which it is capable.

ART. IV. POPULAR PRINCIPLES RELATING TO THE LAW OF AGENCY.*

SUCCESS in mercantile life, is founded mainly upon integrity, industry, and perseverance. It does not require that wealth, connexions, or rank, should smile upon the young aspirant. The large fortunes and the high influence which we see bestowed upon the distinguished merchants of our city, have, in few instances, arisen from the advantage of early wealth, or the countenance of great connexions. But these fortunate and prosperous men are generally to be traced to some obscure post in early life; to some country school which has sent forth its pupils equipped with some arithmetic, some grammar, some geography, but no rhetoric, logic, or philosophy, into the more laborious posts of our towns and villages. There the beginner has learned first to endure labor and bear privations-to acquire in this way habits of selfdenial and hardy perseverance; and there has made honesty and good faith virtues not difficult to practice. They have learned also in this manner, from necessity, habits of economy; and when called upon to act for others, their virtues have shone out, they have attracted confidence, been favored with credit, have had a scope thus opened for their enterprise and capacity, and by persevering energy and prudence, have finally established the fortunes of princes-clothed themselves in purple, and built for themselves palaces. Such examples are shining upon us here from every quarter, and serve at the same time to guide and cheer on those who are following in the same course of usefulness.

In the progress of a person thus commencing, without wealth, and unsupported by rank, the first condition of his life will be, to bestow his services in the business of some other. He is his clerk; then becomes more confided in, and acquires more experience, and becomes a supercargo, an agent, or a factor, acting for the behalf of another, and in his absence, but upon his instructions and upon his authority and credit. He is now properly an agent. He advances still farther in knowledge of business, and in the confidence of those who witness his conduct, and is associated with some person needing his qualities, as a co-partner; and after having fully satisfied his own desires for extended business, and become earnest for the rest which years renders grateful, and wealth renders attainable, he himself calls in and patronises some young man as clerk, or partner. And in all the stages of his course, he finds it necessary at times either to call upon some friend to stand as his surety, or is called upon by some other to discharge this friendly office. It is thus that the relations growing out of agency, co-partnership, and suretyship, present themselves, of extensive application and general interest. They are, therefore, selected as topics upon which useful and popular instruction may be given: topics which may enable us to present some views of law, and of the principles of justice, which may not be wearisome, and which will enable me perhaps to fix myself in the recollections of my audience, as having been a useful as well as well-intentioned counsellor.

The great extent of these relations, and of the principles of law applicable to them, will prevent a very minute exposition of detail; but will afford the

A lecture read before the Mercantile Library Association of New York, by Daniel Lord, Jun., Esq., on the 27th of January, 1835, and politely furnished by the author for publication in our Magazine.

opportunity of exhibiting very many interesting principles; and in every instance, it will be our endeavor, rather to consider the principle upon which our law is founded, than to seek to give the numerous nice distinctions and exceptions to which all general rules are subject, which render the law a distinct profession and science, and call forth the utmost displays of learning and sagacity.

In the course of the Merchant, as above alluded to, the starting point is the situation of a clerk and agent: with the discussion of the principles applicable to that relation, we therefore commence.

The duties of a clerk are so generally under the immediate direction and conduct of his principal, that they need no explanation in the law: his acts are, in fact, almost absolutely the personal acts of the principal

himself.

An Agent is one who acts on the behalf and by the authority of another. And his acts are deemed those of this other person, who is called his principal. Our purpose is chiefly to consider those agents, who are not acting under the very eye and in the personal presence of the principal; for such a state can give rise to few relations: but to those who act for others not present, and who therefore represent their principal's interest; who may err, to their own detriment; who may do acts embarrassing or injurious to their employer; or who may be the means, however innocently, of contracting nugatory arrangements with others, relying on their good faith, through a want of authority or other peculiarity of their situation.

The first particular to be considered is, that the agent acts in behalf of another. If while agent he acts upon his own behalf, either without the scope of the business in which he is engaged as agent, or acts in his own name, and professedly for his own benefit, neither he nor the persons with whom he deals, can have any connexion with the principal. Obviously here the agent cannot claim his principal's protection, or his adoption of such an act. Nor can the stranger dealing with him, who does not intentionally contract with a principal not presented to him as a party, and who therefore can only be supposed to rely upon the actual contracting man, make any claim in justice upon the principal. In such a case the prin-cipal has been left out of sight altogether, and can only come into view at his own choice.

But can he at his choice come in to such a transaction, and make himself a party and claim the benefit? In some cases he may. If in such a departure from his agency, the agent has employed the funds of the principal, either property or credit, the principal has a right to say, "you could not honestly employ these funds but in my service: you cannot pretend against me, that you intended a dishonest misappplication of them: although you have gone out of your duty, so that I am under no obligation to sanction what you have done, yet I choose to do it, and unless you confess yourself a dishonest man, you cannot object to it." This argument is sound in law: and in such a case the agent exposes himself, if the adventure is a losing one, to bear the loss, and if a gaining one, to lose the profit. And as he has violated his duty, he can make no just complaint, nor receive any honest sympathy.

In the event also of an agent who has given to his principal the disposition of all his time or services, whatever he does, may be claimed by this principal, who has a right to say, that the time and services were his, and that the fruits they have yielded shall fall into his lap. This, however, is a case of very different merit on the part of the agent: and if he has not neglected his principal's affairs, the latter would be using his rights at least harshly, to