lower arcs and parts of arcs correspond to brackish and fresh-water beds The most unmixed fresh-water formation, the Osborne, coincides with the two lowest arcs, 4′ and 5′.

For the sake of comparison, we will again carefully go through the profile of the Paris Basin, and compare this with Stockwell's curve, commencing from the bottom. The beds are numbered in the same way as in the original description of Dollfus and Vasseur (Bull. Soc. Géol. Fr., 1878, sér. 3, tom. VI, pp. 243, et seq.).

Sables de Beauchamp et Mortefontaine, etc., beds 89 to 111. Arc 14 and first half of 15. In this series we have, first five marine sandstones alternating with sand; then a limestone and a calcareous marl, with intercalated sand and marl. Thus in all six or seven alterations.

Calcaire de St. Ouen, beds 112 to 142. A fresh-water formation which is divided by a marine deposit (128) into two subdivisions. In the lower part (from the summit of arc 15 to the summit of are 16) there are four horizons of hard limestone and siliceous limestone with intercalated marls. Then comes the marine bed (at the summit of 16). It must be remarked that the corresponding arc in Leverrier's curve reaches higher up. In the upper division of fresh-water limestones we have six alterations of hard limestone and siliceous limestone with marl and clay. This division therefore finishes a little to the left of the summit of arc 2'.

Sablas de Monceaux, beds 143 to 145. Marine sand with three Septaria layers. The rest of arc 2'.

Marnes à Pholadomya, beds 146 to 154. Marine, with two alterations of siliceous limestone and marl. The first part of arc 3'. •

Gypsum No. 3, beds 155 to 158. Marine marl and gypsum, one alternation, and Marne à Luciana, bed 159. The rest of arc 3'. (The beds 146 to 159 thus have together spond to the arc 3'.)

three alternations and corre

Gypsum No. 2, beds 160 to 196, arc 4'. Marine, at any rate for a great part. But it must be remarked that no fossils have been cited from the last part of this series. Gypsum alternating with marls about five times. The most important gypsiferous horizons are the beds 161, 171 to 176, 178 to 188, 191 and 194.

Gypsum No. 1, bed 197, 8 meters thick, with fresh-water animals. One alternation. Between arcs 4′ and 5′.

Marne bleue, beds 198 to 204, and Marne blanche, beds 205 to 209, fresh-water marls alternating with marly limestones and ferruginous marls about four or five times. Arc 5′ and the first third of are 6'.

Marne verte, beds 210 to 217, a brackish-water formation with two al ternations of clay with marl and siliceous limestone. The upper part

of arc 6'.

Calcaire de Brie, beds 218 to 220, a fresh-water limestone. Perhaps we have here indications of several climatic alternations, for limestones occur alternating with marl three or four times, though certainly in very thin beds. Its place is in the hollow between arcs 6' and 7'.

Marne et Molasse Marine, beds 221 to 231. Clay alternating with marly limestone and sandstone three or four times. The upper part of arc 7'.

Sables de Fontenaye, bed 232. Marine sand with a few layers of clay, but without marked alternations. The latter part of arc 7'.

Calcaire de Beauce (p. p.) Fresh water, between arcs 7' and 8' From this we get a complete agreement with the palæontological results, as shown by the following comparison of the equivalent formations in both basins:

It will be seen that the number of alterations of strata is about the same in the synchronous formations in the Paris and Hampshire Basins. This shows that this alternation of strata was due to a general cause; and that this cause is the precession of the equinoxes, seems highly probable.

As moreover the curve of the eccentricity of the earth's orbit ap pears at the same time to be a curve of the variations of the sea-level, we may also conclude with probability that for one reason or another the sea rose and fell with the eccentricity.

TIME-KEEPING IN GREECE AND ROME.*

By F. A. SEELY, of the U. S. Patent Office.

In my room in the Patent Office there hangs a Connecticut clock of ordinary pattern and quite imperfectly regulated. Its variation of perhaps half a minute in a day, however, gives me no concern, since being connected by wire with the transmitting clock at the Naval Observatory, it is every day, at noon, set to accurate time. At the moment of 12 o'clock there comes a stroke on a little bell and simultaneously the three hands, hour, minute, and second-whether they may have gained or lost during the preceding twenty-four hours, fly to their vertical position. Immediately after I hear a chorus of factory whistles, sounded in obedience to the same signal, dismissing the workmen to their midday meal. At the same moment and controlled by the same impulse, the ball, visible on its lofty staff from all the ships in New York Harbor, drops, and the seamen compare their chronometers for their coming voyage. The same signal is sent to railway offices and governs the clocks on thousands of miles of track and determines the starting and stopping and speed of their trains. It goes to the cities of the Gulf and of the Pacific as well as to those of the Atlantic coast-noted everywhere as an important element in the safe, speedy, and accurate conduct of commerce; and so the work of the regulating clock of the Observatory, sent out by means which note the minutest fraction of a second of time, is playing its important part in the economy of our century. I can not follow it out in detail; every one will do so to some extent in his own mind. But if we were to divide human history into eras according to the minuteness with which the passage of time is observed in the ordinary affairs of life, we should find ourselves to have arrived, and very lately, in what might be called the era of seconds.

At the opposite extreme is the period when the passage of day and night reveals itself to the dullest intellect. Perhaps no savage people have ever been so dull as not to have noted more than this. We can hardly conceive a state in which the brutal hunter did not take note of the declining sun and observe that the close of the day was approach

* Read before the Anthropological Society of Washington, April 5, 1887. (From the American Anthropologist for January, 1888, vol. 1, pp. 25–50.)

ing. The lengthening of his own shadow was an always present phenomenon, and men must have observed shadows almost as soon as they became capable of observing anything. But this kind of observation went on for ages without any attempt to sub-divide the day, and none but the great natural periods marked off by sunrise and sunset were recognized.

Between this period, marked by the observation of the natural day only, and that in which we live, there have been many steps of progress, the very dates of which may in some cases be quite distinctly observed. We find an era where noon begins to be noted, and the natural day is equally divided by its observation. Then we find an era in which either the entire day or its great natural fractions are again divided into smaller fractions of rather indefinite length, as is now done by some savages and as was done in the earlier history of Greece and Rome. Next to this comes the era in which definite artificial fractions of the day are observed, which may be called the era of hours. It was many centuries after this before men in the ordinary transactions of life counted their time by minutes, but the time when this began is quite distinctly marked.

I would not say that these eras are contemporaneous in all nations, nor could I assert that they correspond closely with any recognized stages in civilization and culture; in fact, the observation of hours of the day does not appear to obtain until civilization is reached. This is true however, men measure most carefully that which they value most, and the value of time is enhanced just in proportion to the multiplicity of the demands upon it which the existing state of society involves. The man who has engagements at the bank, the custom-house, his own warehouse or factory, and in a court-room, and a dozen or more individuals to meet, each of whom, perhaps, has similar pressing engage. ments, and then must reach an express train at 4:30 in order to dine at 6, fifty miles away, must allot his time with the greatest care and measure it with the utmost minuteness. To the savage, the sun rises and sets, and rises again;-one day is as another; nothing presses but hunger, and that he endures till fortune brings food. He needs no clock to tell him it is dinner time, for it is always dinner time when there is food. When people travelled leisurely by stage coach, walking up the hills to rest the horses, stopping at the wayside inns to dine, and well content at the close of the day if 50 or 60 miles had been covered, seconds of time and even minutes were of little account; but when trains are run on a complex schedule, and for a whole season in advance it is set down at just what place each train must be at each moment of every day, and the safety of lives and property depends on exact adherence to the prescribed order, then the station clocks must be invariable and synchronous and the conductor's watch true to the second. Civilization is marked at every step of its progress by the multiplication of the varied relations between men, and since the importance of time is enhanced