Popular Science Monthly/Volume 45/July 1894/A Colonial Weather Service
By ALEXANDER McADIE, M. A.
THE Signal Service was thoroughly organized as a meteorological body in November, 1870. As Americans we are justly proud of the work accomplished by it and its immediate successor the Weather Bureau. Toward the establishment and success of the meteorological service the army, the navy, and civil life contributed representative men: Myer, the soldier physician, dubbed by his countrymen "Old Probs"; Maury, the seaman whose pen could trace on many pages descriptions ever pleasing and instructive; and Ferrel, citizen professor amid military men, one so diffident and reserved that he carried to and from the meetings of the National Academy, of which he was a member, manuscripts of problems solved, which he would have liked to make known but that a strange shyness prevented. Forecasting weather changes had, however, been suggested earlier than the date above given. It is said that the French war office, during the siege of Sevastopol, sent to the allied fleets before the fortress information that a tempest was raging west of the Crimean Peninsula. In the United States, Redfield, Espy, Coffin, Loomis, Henry, and Lapham had argued the possibility of forecasting weather changes if systematic simultaneous observations could be had. Antedating all of these stands that uniquer philosopher, the printer of Philadelphia, who had discovered, before the middle of the eighteenth century, that "our northeast storms come from the northwest." Before Franklin, however, came his correspondent. Dr. John Lining, of Charleston, S. C, who kept a record of the daily temperature in 1738. Thermometers had then been in use but a few years. But the observations which were the most remarkable of all, and which up to the present time have been unnoticed if not indeed unknown, were made in Virginia about the time of the Revolution. The observers were James Madison, styled by that charming old traveler, the Marquis de Chastellux, "an eminent professor of mathematics"; and Thomas Jefferson, the Sage of Monticello. One was at Williamsburg, the colonial capital, practically near the sea; the other at Monticello, one hundred and twenty miles west and north, practically in the mountains.
These two colonial gentlemen operated a weather service; on a small scale it is true, but the observers seem to have clearly recognized that great underlying principle of all modern weather
Forecasters at Work, in Washington.
bureaus, the taking of observations simultaneously. This, if established, removes the palm of priority from Le Verrier and France to our own country. True, no map was issued; but a century before either Le Verrier or the Signal Service, the principle which makes the map possible was thought out and tried with the best agencies at hand. Had the telegraph been in existence, there is no telling what these acute-minded colonists would have attempted.
Madison was by training and inclination a man of science, and no one can disparage Jefferson's activity as an observer. It was the practice of the latter to read his thermometer every day either at sunrise or at nine in the morning, and at sunset or four in the evening. Even the calls so frequently made upon him for active service elsewhere, while interrupting the Monticello records, did not prevent his taking observations as he journeyed. In his private expense account we find records of temperature, rainfall, and weather jotted down with as much care and detail as expenditures. In some pages at the end of the book, the title-page of which reads, "The Philadelphia Newest Almanac for the Year of our Lord 1776, being Leap Year, . . . By Timothy Telescope, Esq." Jefferson has noted for the years 1776, 1777, and 1778 his personal expense items and detailed systematic records of temperature and rain. We turn the pages of this rare old diary slowly and there are some entries on which the eye lingers, while one wonders why these pages have not received the attention of historian and meteorologist.
On July 4, 1776, he jotted down among his expenses:
And on July 8th the same year:
Sparhawk, I surmise, was an instrument-maker, and the price paid for the thermometer indicates an instrument of high order. From intimations in various places one can almost believe that the purchase of this high-priced instrument was regarded by Jefferson as an act of self-indulgence. Whether it served to relieve the mental strain incident to the doings of that ever-memorable week, or whether he was simply eager to study the new acquisition, certain it is that the entries are more than usually frequent. There, in Jefferson's own fine hand, stands the record of his observations:
The fourth of July, 1776, was, then, relatively cool. I think statements to the contrary have been made, and the day described as hot and sweltering. More than one historian may have drawn upon imagination in describing the weather of those first days in July when the signers of the Declaration were gathered together in Philadelphia. Strange that from the same hand that penned the Declaration should come at this late date a true statement of the weather of that period. One can not help a feeling of surprise that Jefferson, with so many duties pressing, should have found time to make these detailed observations.
The Colonial Weather Service experienced all the vicissitudes of war. Madison writes to Jefferson somewhat pathetically as follows:
"I wish we had a barometer; but there is no possibility of getting one here at present. The British robbed me of my thermometer and barometer." This must have been a serious loss to the colonial meteorologists, although to us there is a touch of the ludicrous in the very idea of British soldiery relieving the college professor of his thermometer and barometer. Perhaps the instruments would have been spared could the commanding officer have foreseen that in a few years, the war ended and the colonies independent, this very professor was to go to England and be consecrated as Bishop of Virginia.
But notwithstanding interruptions, our meteorologists persevered, and their long-continued correspondence is full of wherefores and whys which even at this day are of interest and meaning. They ascertained "by contemporaneous observations of between five and six weeks" that "the averaged and almost unvaried difference of the height of mercury in the barometer at these two places was 0·784: of an inch; the pressure at Monticello being so much the lightest—that is to say, about a thirty-seventh of its whole weight.Furthermore—and this is truly remarkable—they proved in their own words "the variations in the weight [meaning pressure] of the air to be simultaneous and corresponding in these two places. "Many data were collected regarding the climate of
A Modern Meteorological Observatory.
Virginia. The value of the work can be judged by Jefferson's statements under Query 7 in his Notes on Virginia:
"Journals of observations on the quantity of rain and degree of heat being lengthy, confused, and too minute to produce general and distinct ideas, I have taken five years' observations, to wit from 1772 to 1777, made in Williamsburg and its neighborhood, have reduced them to an average for every month in the year, and stated those averages in the following table, adding an analytical view of the winds for the same period."
Then follows quite a long table of average temperatures and wind directions of great interest to the meteorologist. Thinking that some noteworthy differences might exist between the northeast and northwest winds at the two stations, a second table was constructed by reducing observations at the two places for nine months to the "four points perpendicular to and parallel to the coast. It may be seen that the southwest wind prevails equally at both places, that the northeast is next to this the principal wind toward the seacoast, and the northwest is the predominant wind toward the mountains; . . . the northeast wind is loaded with vapor insomuch that the salt-makers have found that their crystals would not shoot while that blows; it brings a distressing chill, and is heavy and oppressive to the spirits; the northwest is dry, cooling, elastic, and animating."
Even our valuable Crop Bulletin was foreshadowed by these early workers. We find it recorded that "white frosts are frequent when the thermometer is at 47º and have killed young plants of Indian corn at 48º, and have even been known at 54. Black frost and even ice have been produced at 381º."
Finally, that much-discussed matter, change in climate, did not escape their notice. "A change in climate," they claim, "is taking place very sensibly." This was written in 1781. "Both heats and colds are becoming much more moderate within memory even of the middle-aged. Snows are less frequent and less deep. They do not often lie below the mountains more than one, two, or three days, and very rarely a week."
And then follows a very evident reference to that even then well-known personage, the oldest inhabitant:
"The snows are remembered to have been formerly frequent, deep, and of long continuance. The elderly inform me that the earth used to be covered with snow about three months in every year."
From snows and winds these meteorologists turned their attention to rainbows, and from rainbows to water vapor and steam. Curiously enough, it is in a letter to Jefferson, mostly about the rainbow, that Madison gives the latest information about a boat to be propelled by steam and which "General W—— and others have seen and approved, and is much discussed by the well-informed; but which I must say I feel skeptical about."
What a contrast! The steam navigation of that date and today; from the first rude paddles of the river steamboat to the triple screws of the transatlantic greyhounds! One naturally asks, "Are we to-day on the verge of a still greater navigation, that of the air?" No modern Madison may yet write that some General W—— has seen and approved, but the signs of its advent are multiplying so rapidly that he would not say, "I feel skeptical about it." If these two alert minds were again on earth, we can fancy Jefferson, always so keenly alive to practical application of knowledge, discussing the outlook as follows:
The meteorologists are exultant. In that latest instrument of the electrical engineer, the telautograph, they see the chance for an advance equal to that made when the first synoptic weather map was drawn. Simultaneity of observation can be improved upon. Instead of sending the observations in cipher twice or thrice per day, continuous records in installments can be sent. But even more than this, the map can be drawn in many places at once. The map is issued daily at a score of cities in the United States. A map is also issued daily at Brussels, Paris, London, Zurich, Hamburg, Rome, Munich, Vienna, Chemnitz, Madrid, Algiers, St. Petersburg, Simla, Brisbane, Sydney, Tokio, and Cape Town. Now one step further. Shall there ever he one great central weather office and one great daily weather map for the whole world, drawn not in one hut a hundred cities at the same moment? Does this seem visionary? It is vastly less so than the actual system in operation for the past twenty years would have seemed to the two colonial gentlemen who more than a century ago read their barometers and thermometers simultaneously and speculated on the possibility of propulsion by steam.
Viewing exact delineation by trigonometrical measurement as the crowning work of geography, Mr. Clements R. Markham pointed out, in a recent lecture, that the exact mapping of the land surface of the globe is still very incomplete, while the delineation of the bed of the ocean has hardly begun. The greatest unknown areas lie in the polar regions Even in Europe there remains scope for detailed survey in many countries. In Africa the unexplored has been diminishing very rapidly, but considerable areas are still virgin. Asia has much new ground to break into. The valleys of in Arabia are almost as little known as the antarctic regions. Lhassa has been unvisited by Englishmen for generations, and a vast region in northwestern Thibet is still a blank on our maps. Nepaul is little known; Kafiristan is absolutely secluded from the European. The maze of mountain ranges and river valleys east of the Himalayas has yet to be unraveled, and the whole interior of Indo China is full of opportunities for research. Korea is yet far from being fully known. The great Malay Archipelago must receive more attention.