highest, that at Yard Station, is 480 feet above the ocean.Rept. U. S. Coast Survey, 1871, 175.

NEW ROUTE BETWEEN AUSTRALIA AND CHINA.

Captain Moresby has brought to the notice of the Royal Geographical Society a new route between Australia and China, which lies to the west instead of the east of the Louisiade Archipelago, and is shorter than the present line of communication by three hundred miles. -13 A, March 6, 1875, 243.

PROGRESS OF BAROMETRIC HYPSOMETRY.

That the investigations of Ruhlmann into the sources of error in the determination of altitudes by means of the barometer has been the beginning of a new epoch in barometric hypsometry is evident from the applause with which his work has been received, and the several attempts that have been made by various meteorologists to carry out the methods of observation recommended by him.

In this connection we notice the publication, by Mr. Schott and Mr. George Davidson, of a short comparative study of the methods of determining heights by means of leveling, of vertical angles, and of barometric measures. This investi gation appears to have been begun in 1860, when the obser vations were first made at two stations about fifty miles northwest of San Francisco; the field work was only completed in 1872, and consisted of hourly observations from early morning until sunset, with meteorological and geodesic instruments. The observations have been carefully discussed by Mr. Schott, and he has arrived at the remarkable result that between these upper and lower stations, and during the period over which the observations extend, the temperature of the intervening stratum of air was nearly constant throughout the entire day. There seems, in fact, no trace of a daily variation, as though the rays of the sun passed through the air without sensibly heating it. For this location, therefore, we must conclude that the daily variation of temperature shown by ordinary thermometric readings belongs mainly to the layer of air in contact with or in close proximity to the earth's surface. The computed altitude of the upper station above the lower one, as compared with the true altitude de

duced from careful levelings, shows that for an altitude of 2000 feet, and on the average of seven days' observations, the upper station is computed to be about eleven meters (that is, about thirty-five feet) too high. What the individ ual discordances are from these mean results is not stated; but judging from the similar results given by Ruhlmann, we are safe in saying that differences of altitude of 2000 feet can not be determined by the barometer within a hundred feet, unless the true temperature of the air is computed by Plantamour's or Ruhlmann's method, and is used instead of the observed temperatures directly given by thermometers. -App. No. 11 U. S. Coast Survey, 1871.

DECREASE OF WATER IN EUROPEAN RIVERS IN THE PRESENT CENTURY.

A suggestive paper has lately been communicated by Mr. W. G. Wex to the Geographical Society of Vienna upon the decrease of water in rivers and sources. The author states that the results of his observations tend to show the constant decrease of the rivers of Germany and an increase of the seas. They indicate that the levels of the German rivers are now much lower than they were fifty years ago, the Elbe having decreased to the amount of seventeen inches, the Rhine twenty-four, the Oder seventeen, the Vistula twenty-six, and the Danube fifty-five. The reason assigned for this is the progressing devastation of forests, which causes a decrease in the atmospheric moisture they attract and convey to the soil, and thence to sources of streams.-12 A, February 18, 1875, 314.

PHYSICAL PECULIARITIES OF THE UPPER VOLGA.

According to Poljakow, who has been exploring the region of the Upper Volga, under the patronage of the Russian Geographical Society, the Scandinavian Finlandic glacier, which at one time covered the Government of Olonez and those adjacent to it, must have stretched far into the basin of the Volga and over the boundaries of the Waldai plateau; and a connection must undoubtedly have existed between the Arctic and Baltic seas by the unequal levels of the lakes formed by the melting of the glacier, the slight remains of which are seen in the existing lakes,

Judging from the fauna, Poljakow concludes that the present upper course of the Volga must have been joined to the middle and lower course at a recent period, and in a measure accidentally. In this respect the Sheksna is to be considered the natural upper part of the Volga, as containing the very same fishes as those of the river Bjelosero.-12 A, June 17, 1875, 134,

PHYSICAL CHARACTER OF RODRIGUEZ.

We owe our first reliable information of Rodriguez to the members of the British party visiting that island for the purpose of making preparations for the transit of Venus. This part of the expedition was warned at the Mauritius that they must take every thing they required for subsistence, as it would be impossible to get any thing at Rodriguez. On reaching the island they found the vegetation very rank, the trees, however, of no great size, rarely forming a thick forest, but scattered singly over the slopes of the island. The most common tree seemed to be the vacoa (Pandanus), of which there appeared to be four species. The undershrub is very dense and spinous, rendering walking through it exceedingly unpleasant. Neither ferns nor mosses appear to be very abundant, but lichens are pretty plentiful. The rocks are largely columnar and basaltic, showing that at some period the island was exposed to volcanic action. Landing on the island was difficult, owing to the extent of the coral reefs.-12 A, October 29, 1874, 529.

EXPERIENCES OF THE BASILISK IN NEW GUINEA.

The recent experiences of the British surveying ship, the Basilisk, under Captain Moresby, to which we have already referred, have added greatly to our knowledge of the character of New Guinea and its inhabitants. To the three races heretofore known upon the island-namely, the Papuans on the south, the Arfaks of the mountainous country on the north, and the Malays of the northwest--Captain Moresby has added a fourth by the discovery of another, probably a mixed race of Malays and Papuans, inhabiting the whole of the eastern peninsula of New Guinea in its northern and southern shores, from about 148° longitude to East Cape, which is in 150° 53', and the adjacent archipelago.

This race, while distinctly Malayan, differs from the pure Malay in being smaller in stature, coarser in feature, thicker lipped, and having more frizzled hair. The race merges into pure Papuan in the neighborhood of Cape Possession. They bury their dead in the ground, and build small thatched huts over them. Their houses, like those of the Papuans, are built on piles, and communicate with the ground by means of a pole notched with steps. They cultivate the ground pretty successfully, using stone mattocks for turning up the soil. Cannibalism appears to be known among them, but prevails only to a slight degree. The men are but slightly tattooed, while the women are tattooed all over in graceful patterns. Unlike the Papuans, they possess the art of making pottery. They are better fishermen than the Papuans, having a greater variety of implements, as well as of canoes. Up to the time of the visit of the Basilisk they seemed to have had very little acquaintance with white men.-12 A, April 24, 1875, 431.

MR. FORREST'S EXPLORATION OF AUSTRALIA.

Mr. John Forrest has succeeded in crossing from the western coast of Australia through the very heart of the only extensive region in Australia hitherto unexplored. He and his companions traveled nearly 2000 miles, keeping close to the twenty-sixth parallel of latitude. They left Champion Bay April 1, and reached the telegraph line September 27. Much of the country passed over was of the poorest possible description, scantily supplied with water. This achievement of Mr. Forrest leaves only the direct and more southern route to Perth to be traversed to complete the data requisite for making known the general character of the West Australian continent.-12 A, X., December 3, 1874, 93.

TOPOGRAPHY OF MICHIGAN.

In a pamphlet entitled "Popular Sketches of the Topogra phy, Climate, and Geology of Michigan," Professor Winchell gives a table of the exact areas of the Great Lakes, which, according to him, are as follows, expressed in thousands of square miles: Superior, 32; Michigan, 20; Huron, 20; Erie,6; Ontario, 6. The total length of lake shore-line within the State of Michigan is 1620 miles. He says that he has attempted to collect all the important information obtained, in running lev

els in railroad and canal surveys, and has obtained data for the heights of six thousand places, which give the levels of the surface of the state at every point along the lines of survey. The planes of reference have all been compared with each other with great care, and all elevations reduced to Chicago city datum, which is low water in Lake Michigan in 1847. Contour lines for every fifty feet of elevation above Lake Michigan have been drawn, and are represented upon the maps accompanying the pamphlet, which presents a good general picture of the surface configuration. These tortuous lines, which to the casual observer may seem to be of little interest or value, will be highly appreciated by every intelligent person, and especially by those engaged in engineering enterprises. From the map it appears that the lake shores are depressed, the surface swelling gently up toward the interior regions; the rise being one or two hundred feet within a few miles, and afterward much more gradual. A few bluffs and steep shores are presented between Saginaw Bay and Lake Huron; but in general the steepest grades are found in the eastern portions of the state. Along the border of Lake Michigan stretches a series of sand dunes, or piles of fine silicious sand, piled up by the easterly winds to a height of one or two hundred feet. Back of these dunes the surface is depressed, and frequently occupied by marshes and lagoons. The average elevation of the interior of Lower Michigan varies from four hundred to one thousand feet, with many marks of the erosions that in post-geological ages have pared down the original surface, and established the existing slopes of the land and even the bottom of the lake. Eighteen summits are enumerated by Professor Winchell. They are usually gently undulating plateaus, through which drainage valleys of moderate depth have been excavated. In the northern peninsula, owing to the want of accurate data, so minute a survey can not at present be entered into. The highest summit on the Marquette and Ontonagon is 1186 feet; while the hills north of Lake Michigama are 1215 feet above that lake; and other points near by reach 1250 feet. Beyond the Ontonagon River the greatest altitude of the Porcupine Mountains is quoted at 1380 feet. Especial attention is called to the fact that the longitudinal axes of the topographical and hydrographical