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On pages 50–51 is a list of authorities cited; to this Professor Coffin intended to add the names of many who had aided him by making or transmitting records of observations. This is an omission that cannot now be supplied. A pencilled statement records his acknowledgment of aid from Dr. Franklin B. Hough, of Albany, N. Y., and grateful mention of President Cattell, and his associates in the Faculty of Lafayette College, for their constant sympathy and encouragement in the work; particularly in services rendered in translations from foreign languages by Prof. Francis A. March, LL.D., and Prof. Augustus A. Bloombergh, Ph.D)., also to Prof. Theodore F. Tillinghast, Mr. Thomas C. Green, of Mechanicsville, N. Y., Prof. J. D. Whitney, of Harvard College, the Rev. David Craft, of Wyalusing, Pa., the Rev. John S. Woodside, of Kapurthala, India, and the Rev. Stephen Bush, of Waterford, N. Y., for aid; and to Mr. Henry Mansfield, of Easton, for care in computing the monsoon influences, most of which were drafted by him,

Professor Coffin records the fact that this work lacks observations known to have been made at the following places, but which he failed to secure, viz. :

Barbacoas, Venezuela, 1852 and 1854.
Firmagungulum.
Gaboon Station, Africa.
Leon, Nicaragua, May and July, 1849.
Manilla.
Ponce, Porto Rico.

Singapore.
At the time of the death of Professor Coffin, in 1873, Series A, and the General
Tables, Series B, were mainly completed. Though all the pages of the latter
Series were numbered in manuscript, here and there were blanks left to be filled.
In the observations from Spain, India, and many places in Zones 10 to 18, the
trigonometrical work and monsoon influences remained to be computed. No Plates
had been prepared.

The supply of these deficiencies was undertaken by his son and successor in the College, Professor Selden J. Coffin. He devised and drew the plates, added the Numerical Index to Stations found in Series A, pages 52–66, revised the entire work, and read the proofs. He also prepared Series C, Velocity Tables, pages 637 to 654, and made the deductions connected with them.

This work has been executed with a feeling of pious regard for the memory of a venerated parent, interest in science, and a devotion which merits special commendation.

The Institution also availed itself of the meteorological knowledge and power of original investigation of Dr. Alexander J. Woeikof, Secretary of the Meteorological Committee of the Imperial Geographical Society of Russia, during his late visit to this country, for a series of deductions and analyses from the tables and charts, which the untimely death of Professor Coffin prevented his undertaking. These discussions and analyses are found on pages 623 to 714, and are wholly from the pen of Dr. Woeikof, who also supplied the material in the form of “ Addenda” at the end of the respective zones, and carefully revised the whole work.

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For the better illustration of Dr. Woeikof's discussion, three plates have been reproduced from the important paper by Alexander Buchan, in the Transactions of the Royal Society of Edinburgh,' and for which acknowledgment is here made. These plates exhibit by isobaric lines the mean pressure of the atmosphere over the earth for the year, and for January and July.

This work is given to the world with confidence that it will be an acceptable contribution to science, worthy of the Smithsonian Institution, and a permanent memorial of one who cheerfully devoted to its preparation much of the energies of a long life.

JOSEPH HENRY,

Secretary S. I. WASHINGTON, November, 1875.

1 The mean pressure of the atmosphere, and the prevailing winds over the globe for the months and for the year, Part II., by Alexander Buchan, M A., Secretary of the Scottish Meteorological Society.— Trans. of the Royal Soc. of Edinb., vol. xxv. 1869.

INTRODUCTION.

ORIGIN AND PREPARATION OF THE MEMOIR ON THE

WINDS OF THE GLOBE.

COMMUNICATED BY PROFESSOR SELDEN J. COFFIN.

The decease of Professor Coffin occurred before he had prepared any descriptive text of this work, save what is given in the Preface, and therefore a monograph found among his papers has special interest, as intimating the probable line of treatment he would have pursued, and indicating topics of research in which he was engaged, or to which his attention had been directed. It appears to be the substance of a statement made to the National Academy of Sciences about two years prior to his death. The title is, “ A History of the Present Condition of an Investigation of the Winds.' Its contents, somewhat abridged, are as follows:

“This is not intended as a formal communication on the Winds, but rather a brief narration of what I have accomplished, after having been engaged for many years in the investigation of the laws that govern the circulation of the atmosphere over the earth's surface, with the attendant phenomena.

The following are the problems investigated :

1st. What is the mean direction of the wind over the different parts of the earth's surface ? Or in what direction does the air, as a whole, move over them?

2d. What is the progressive motion of the air in this mean direction? Or, if data be wanting for determining this in miles--and we assume that the average velocity of winds from all points of the compass is the same-during what proportion of the time must the wind blow in this mean direction, so that if the remainder of the time were occupied by calms, or by winds whose conflicting movements neutralize each other, the resulting general progressive motion of the air, as a whole, would be the same as it now is ?

3d. What is the direction and amount of the force that deflects the wind from its mean annual direction in any given month, or season of the year? Or, in other words, what must be the direction of a wind during any given month or season of the year, and during what proportion of the time must it blow, so that combined with the movement of the air in its mean annual direction, it may afford

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a resultant the same as that for the month or season? The former may be regarded as the wind that would exist if the surface of the earth were homogeneous, and the sun ever over the equator; and the latter as that which is due to the change of temperature in the different parts of the year, in connection with the character of the neighboring regions, chiefly with respect to land and water. These deflecting forces, which are found almost everywhere, I denominate monsoon influences, and where they are so great as to decidedly control the direction of the current, the resulting winds are the well-known monsoons.

4th. What relation exists between the direction of the wind and the pressure of the atmosphere? Or, what winds are, on an average, attended by a rise in the barometer, and what by a fall, and at what average rate ?

5th. Also what connection exists between the direction of the wind and the pressure, temperature, and humidity of the atmosphere, the state of the sky, and the amount of rain-fall ?

“These are not the only questions of interest connected with the study of the winds (for their relations to hygienic and agricultural considerations merit close investigation), but they are the only ones to which I have given much attention. And, as to the latter, my investigations have been confined chiefly to the point first named in it. - The

proper scientific investigation of each of these questions is comparatively of recent date, extending back not much further than the year 1830. Vast collections of observations on the winds had been made previously, which are now of invaluable service under the improved methods of studying them; and some of the more obvious phenomena, such as the trade winds,' monsoons, and regions of calms, were well known. But the usual, and indeed the only method of discussing observations of the winds, was to sum up the number that was observed from each of the several points of the compass, to regard that direction which afforded the largest sum as the prevailing direction, and to make no account of the rest. This method often served to point out the geographical features of the surrounding country, rather than to afford any information of value in regard to the real question discussed. It was about the year 1836, perhaps a little earlier, that the idea of resolving the traverse of the winds on the principle now so familiarly known as Lambert's formula, first occurred, nearly simultaneously, to Prof. Kaemtz in Europe, and to Prof. Loomis and myself in this country, to each without the knowledge of the others. [This method is fully described and the formulæ stated in the Preface to this work.]

“My first efforts were directed to the winds at Dartmouth College, New Hampshire, as then reported monthly in the Vermont Chronicle, 1836, and having soon afterward removed to Ogdensburg, New York, I applied the method to the winds there, as recorded momentarily by a self-registering vane that I had constructed for the purpose.

The results at the latter place were published in the annual report of the Regents of the University of the State of New York for the year 1838.

“In the year 1824, the Legislature of New York had made an appropriation for establishing a system of meteorological observations at different academies in the

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