inquirer, and be likely to prevent fulness and accuracy. The mode of approach, and the questions asked, to obtain the same information, may be varied and adapted to the circumstances of different cases. And discretion will be a qualification ever to be possessed by the enumerator.

XIII. COMMUNICATION FROM WILLIAM C. BOND, Esq. [See p. 149.] Observatory, Cambridge, Nov. 30th, 1849.

My Dear Sir,-Herewith I return you, with my thanks for its perusal, the pamphlet on "Meteorology as connected with the Public Health in England." By James Glaisher, Esq., Superintendent of the Magnetical and Meteorological Observations made at the Royal Observatory, Greenwich.

Since our conversation on the subject in July last, I have brought it up before several of my friends who take an interest in such matters, and I have found them unanimously of the opinion, that if our Legislature should see fit to encourage similar meteorological investigations within our own Commonwealth, much valuable information in regard to the laws which govern our atmospheric changes might reasonably be expected to result from them.

But it is absolutely necessary that the observations upon which such investigations are to be based, should be conducted upon a uniform, well-digested system, continued through a series of years, and finally be put into the hands of a competent person for careful combination, comparison and discussion.

In reply to your inquiries respecting the instruments and kind of observations which would suffice to render useful such establishments as those referred to in the English report, I need only be very brief, as in the event of the Legislature adopting the proposed plan, some person familiar with these matters will doubtless be appointed to superintend the work.

The apparatus required for a meteorological station need not be very expensive. It will be sufficient that each observer be furnished with a good barometer, a standard thermometer, two wet bulb thermometers, a rain gauge and a wind vane. To these should be added blank forms for registering his observations.

The barometer should be graduated to ENGLISH inches, and decimal parts, reading by vernier to one five hundredth part of an inch.

The English division is preferred, because nearly all the instruments of this sort in this country are so graduated, and it would afford a more ready comparison of observations with others. There is no important advantage to be derived from a change in this respect, while on the other hand, a variety in graduation creates confusion.

It will be advisable to have all the barometers so constructed that the quicksilver at the lower surface may be easily adjusted at every observation to a constant distance from the zero of the scale. The attached thermometer may have its bulb inserted in the cistern; or it may be placed in contact with the glass cylinder containing the column of mercury, near the base.

Great care must be taken to have the standard thermometers accurately graduated. The wet bulb thermometers, which are to be used as psychrometers for ascertaining the dew point or hygrometric condi-

tion of the atmosphere, are to be compared in their dry state with the standard, and any difference noted in the journal. A cubical box of zinc, ten inches by the side and open at top, with an interior flange, answers the purpose of a rain gauge, presenting a surface of one hundred square inches; the amount of rain fallen is readily ascertained by either weighing or measuring.

The wind vane should be well balanced, not too light, and the car dinal points, indicating the direction, set to correspond to the heavens; or the north point of the horizon in this State may be taken for the present at 9° 30" east of that indicated by the magnetic compass.

It is of the first importance that all the observers should adopt one uniform system in respect to time, mode of observing, and nomencla ture. The journals will then speak a common language, which will greatly facilitate the labor of reduction, comparison and discussion.

No other than general instructions need here be given for the arrangement of the instruments, as probably at no two stations can they be precisely similarly situated. The barometer ought not to be subjected to great and frequent changes of temperature; the ordinary sitting room, where an equable temperature is usually maintained, is both a convenient and proper situation for it.

The external standard thermometer should be placed on the north side of the house, on a bracket not less than six inches from the walls, so as to allow a free circulation of air round it; and it should be care fully guarded from radiation from other buildings or from the open ground; every particular regarding the situation and condition of the instruments should be carefully recorded in the journal.

It would add greatly to the interest and value of the work if each observer should, from time to time, make note of any natural events that may occur under his own eye, such as the time of flowering of plants, the temperature of springs, and of deep wells; every appear. ance of the aurora borealis, particular notice of thunder storms and of meteors, the time when they are first seen, the magnitude, duration and apparent path. In fact so much interesting and valuable infor mation would result from the establishment and faithful conduct of such stations, and at a very trifling cost, that I cannot but hope our Legislature will give the subject a serious consideration.

In regard to the hours proper for regular observation, much must be conceded to the convenience of those who undertake the task, as I understand they will be expected to give their time without any other remuneration than the consciousness of aiding in a good work. Surely the Legislature would be justified in granting something additional, where the result of the labor is likely to benefit the whole community. The hours adopted at this place for meteorological observation, are sunrise, 9 a. m., and 3 and 9 p. m. Sunrise we consider an important point, and it is usually the period of greatest cold; 9 p. m. is near the mean temperature of the twenty-four hours. The hours of maximum and minimum barometer would probably be found inconvenient to You will not, I suppose, be able to obtain more than three daily observations steadily continued; it would be well that two of these should correspond to the hours adopted at fixed observatories. This point ought to be settled definitely, and, once decided upon, should be strictly adhered to through the whole series.

many.

In regard to the distribution of the stations, Newburyport, Boston, (or Cambridge,) Plymouth, Provincetown, and Nantucket, for the sea coast-Worcester, Amherst, Princeton, Northampton and Williamstown, in the interior, seem to me to be favorably situated for watching the progress of storms.

These are the principal points which occur to me at this moment, as needful to be attended to.

Respectfully and truly yours,

W. C. BOND.

To LEMUEL SHATTUCK, Esq.

XIV. EXTRACTS FROM THE REPORT OF THE REGISTRAR GENERAL.

[See page 149.]

The publication to which Mr. Bond refers contains weekly, monthly, and quarterly abstracts of the atmospheric observations made at the Royal Observatory, or compiled from those made at other places in England. The tables contain admirable formula for such observations, and should be carefully studied before adopting a plan for Massachusetts. They are, however, here omitted. We subjoin extracts from the "Remarks on the weather during the quarter ending September 30, 1848," and for the week ending July 28, 1849, which accompany the tables, as an illustration of the manner in which this part of these reports is prepared :

With the exception of a few days in July, and the period between the 9th and 23d of September, the weather during the quarter ending September 30, 1848, was wet, with very little sunshine. The month of August was extremely wet, and in many places the falls of rain, both in July and September, were unusually great. So much rain falling in a period immediately following the previous bad weather, renders the season and the year very remarkable. On July 1, the mean temperature of the air was 8°4 below the average value of the same day in the seven preceding years, and on the 6th it was 12°2 in excess above the average; on the former day the mean temperature was 46°7, and on the latter day it was 74°0. On the 9th, it was 3° below the average, and on the 14th it was 9°4 above the average; and on the 15th it was again below the average. These changes were great and abrupt. From July 11 to September 19th the temperature of the air was almost always below the average value, and particularly so between the 11th and 15th of September; on the 12th, the departure from the average was 12°6. From the 20th of September to the end of the quarter the temperature of the air ranged somewhat above the average value. The hottest day in this year was July 6, and this day was the hottest all over the country. On an average of seven years the hottest day is July 5.

In pursuance of the arrangement hitherto followed, I will speak of each subject of investigation separately.

The Mean Temperature of the Air at Greenwich

For the month of July was 61°5, which is 3°7, 1°3, 0°6, 0°1, and 1°7 above those of the years 1841 to 1845 respectively, 3°0 and 3o9

below those of the years 1846 and 1847; or it is 0°1 above the aver age of these seven years.

For the month of August was 58°5, which is 2o0, 6o9, 3o6, 4°7, and 3°6 below those of the years 1841, 1842, 1843, 1846 and 1847, respectively, 0°8 and 1°2 above those of the years 1844 and 1845, respectively, or it is 207 below the average of these seven years.

For the month of September was 55°8, which is 2o3, 0°6, 3o7, 1o1, and 4°3 below those of the years 1841, 1842, 1843, 1844 and 1847, respectively, 1°2 and 1°5 above those of the years 1845 and 1846 respectively, or it is 1°2 below the average of these seven years.

The mean value for the quarter was 58°6; that for 1841 was 58°8; for 1842 was 60°7; for 1843 was 60°8; for 1844 was 58°7; for 1845 was 56°9; for 1846 was 62°6; and for 1847 was 60°3; so that the defect for this quarter below the corresponding quarter in the years 1841, 1842, 1843, 1844, 1846 and 1847, was 0°2, 2°1, 2°2, 0°1, 4°0 and 107 respectively; the only year between 1841 and 1847, whose mean temperature for this period was less than that for the present year, was 1845; and the difference is 1°7. The average value for this quarter from the seven preceding years was 59°8, so that the mean temperature of the air for the quarter ending September 30, 1848, was below that of the corresponding quarter in the preceding seven years by 1°2.

The Mean Temperature of Evaporation at Greenwich For the month of July was 57°6, which is 0°1 above that for the preceding seven years.

For the month of August was 55°2, which is 2°9 below that for the preceding seven years.

For the month of September was 53°2, which is 1°5 below that for the preceding seven years.

The mean value for the quarter was 55°3, which is 1°4 below the average for the seven preceding years.

The Mean Temperature of the Dew Point at Greenwich For the month of April was 54°6, which is 3°0, 1°4, 0°2, 1°9, and 1°8 below those for the years 1841, 1842, 1845, 1846 and 1847, respectively; 107 and 0°1 above those for the years 1843 and 1844 respectively, or it is 0°9 above the average of these seven years.

For the month of August was 52°8, which is 2°2, 6°1, 5°0, 4°7, and 3°3 below those for the years 1841, 1842, 1843, 1846 and 1847, respectively, 0°5 and 0°2 above those for the years 1844 and 1845, or it is 2°9 below the average for these seven years.

For the month of September was 50°9, which is 2°8, 2o6, 4°0, 2o3, and 4°0 below those for the years 1841, 1842, 1843, 1844 and 1846, respectively, 1°2 above those of the years 1845 and 1847, or it is 1°9 below the average of these seven years.

The mean value for the quarter was 52°8, which is 1°3 below the average for the corresponding period of the preceding seven years. The mean weight of water in a cubic foot of air for the quarter was 4.5 grains, which is 0.2 less than the average for the seven preceding years.

The additional weight of water required to saturate a cubic foot of air was 1.1 grain. The average value for the seven preceding years was 1.0 grain.

The mean degree of humidity of the atmosphere for July was 0.762, for August was 0.797, and for September was 0.795. The averages for the seven preceding years were 0.780, 0.804, and 0.842 respectively. The value for the quarter was 0.785, which is 0.024 less than the average for these years.

The mean elastic force of vapor for the quarter was 0.411 inch, which is 0.026 less than the average for these years.

The mean reading of the barometer at Greenwich for July was 29.836 inches, for August was 29.732 inches, and for September was 29.832 inches; these values are 0.041 inch above, 0.065 inch below, and 0.021 inch above, respectively, the averages for the seven preceding years. The mean value for the quarter was 29.797 inches, which is of the same value as the average for the seven preceding years.

The average weight of a cubic foot of air under the average temperature, humidity and pressure, was 527 grains; the average for the seven preceding years was 526 grains.

The rain fallen at Greenwich in July was 2.1 inches, in August was 4.6 inches, and in September was 2.4 inches. The average amount for the seven preceding years was 2.3 inches in July, 2.7 inches in August, and 2.2 inches in September. The amount fallen in the quarter was 9.1 inches, which is 1.9 inches greater than the average for the seven preceding years. The average fall of rain during this quarter, as derived from the observations since the year 1815, is seven inches. In the year 1824 the fall of rain in the quarter ending September 30 was 9 inches; in 1828 it was 12.5 inches; in 1829 it was 11 inches; and in 1839 it was 10.5 inches. The total amount of rain fallen this year till September 30 was 24.3 inches; in 1841 it was 21.2 inches; in 1842 it was 14.2 inches; in 1843 it was 17.5 inches; in 1844 it was 16.2 inches; in 1845 it was 16.6 inches; in 1846 it was 17.5 inches; and in 1847 it was 11.6 inches; so that the fall of rain this year exceeds that in 1841 by 2.7 inches, in 1842 by 9.7 inches, in 1843 by 6.4 inches, in 1844 by 7.7 inches, in 1845 by 7.3 inches, in 1846 by 6.4 inches, and in 1847 by 12.3 inches. The excess of the fall of rain this year over the average for the seven preceding years is 7.5 inches.

In the years 1824 and 1828 the depth of rain fallen to the end of September exceeded 23 inches; and in the years 1829 and 1839, the amount collected exceeded 20 inches. So large a fall as 24.3 inches within the first nine months of the year has probably not been exceeded within this century.

The temperature of the water of the Thames was 63°0 by day, and 62° by night. The water, on an average was 3°9 warmer than the air. The horizontal movement of the air was about 130 miles daily; during the period of time between July 19 and July 27, it amounted to 233 miles per day; from July 31 to August 6, its average daily value was 240 miles, and on August 21 it exceeded 300 miles.

The highest and lowest readings of the thermometer in air, at the height of four feet above the ground, and protected as much as possi ble from the effects of radiation and rain, were 85°3 and 32°8.

The average daily ranges of the readings of the thermometer in air, at the height of four feet, were 22°5 in July, 18°5 in August, and 20°9 in September. The average ranges for these months, from the obser