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striking manner the predominant slopes and elevations. Besides this, the marine currents, the lines of equal temperature, the zones of vegetation and other physical phenomena are indicated. While these maps are not deficient in details, one of their chief merits consists in the fact that what is minute and special is made subordinate to what is general and extensive. By a skillful mode of drawing, those features of a country which constitute its chief characteristics are brought prominently before the eye, while the minor features are less boldly presented. At a glance it is easy to recognize what mountain chains, table lands, or water courses distinguish one continent or region from another; while a more careful scrutiny will bring out some of the details of the structure. The object seems never to have been lost sight of, that in such general maps as these, the essential, the predominant, the characteristic, should be given in clear, bold, lines; while that which is secondary and unimportant should either be omitted altogether or delineated in a subordinate style. Consequently the maps are not encumbered with minutiæ. They are eminently fitted for instruction in a class. Special topography can be acquired in hand-atlases, where an abundance of names is a merit rather than a superfluity; but in the lecture and the recitation such details are confusing to the eye and embarrassing both to the pupil and the teacher.

In addition to the exhibition of natural phenomena, the chief political divisions and the principal towns are also indicated on these maps, in a manner which does not obscure the physical features. The lettering is also well managed. Names are sufficiently frequent but are so printed as not to crowd the map, and indeed so as not to be read at the distance of a few feet. By devices of this kind, a great deal of detail is introduced without overrunning the map, and destroying the simplicity and clearness which are so important.

We have seen completed of this series only the maps of South America and the United States, but we understand that others are ready for publication. (New York: C. Scribner, 1863.)

PROF. WHITNEY ON THE HIGHEST MOUNTAINS OF THE UNITED STATES AND OF NORTH AMERICA.-Prof. J. D. Whitney, Superintendent of the California Geological Survey, discusses briefly in the California Proceedings, ii, 219, the question "which is the highest mountain in the United States and which in North America?" His conclusion is that Mt. Shasta, the height of which according to the barometrical measurements of the California Geological Survey, is 14,440 ft., probably overtops all other peaks within the limits of the United States. Mt. Hood, sometimes called the loftiest peak of the Cascade Range, is probably not so high as Mts. Shasta, Rainier, or Adams, and by no

AM. JOUR. SCI.—Second Series, VOL. XXXVII, No. 109.—JAN., 1864.

means entitled to the supremacy of the chain, although one of the highest points in it. Dr. Vansant's trigonometrical meas urements in 1860 are reported to have given the height of Mt. Hood as 11,934 feet.

Mt. St. Elias has generally been considered the highest mountain in North America on the authority of Malespina's manuscripts, discovered by Humboldt in the archives of Mexico, which assign to it an elevation of 17,854 feet. The following circumstances, in the view of Prof. Whitney, justify us in believing that Malespina's measurements were grossly incorrect.

"In the first place," he remarks, “La Perouse measured this mountain in 1786-8, and made it only 12,661 feet high; again, on the English Hydrographical Charts, it is given at 14,970 feet. But, secondly, Vancouver, in his description of the mountain, says expressly that the snow line does not descend very far down its sides, which would be an absurdity, if it was really 17,000 feet high in a latitude of sixty degrees. It is probable that the height given by the British Charts, probably from Captain Denham's measurement, is nearer the truth; and, if so, then St. Elias is nearly 3,000 feet lower than Popocatapetl, and also lower than several other points in Mexico, and lower than Mt. Brown and Mt. Hooker, in British Columbia, according to the usually adopted figures, viz: 16,000 and 16,750 feet. But, it may be said with truth, that these figures given by Douglas are of little value, and that they are considerably above the real heights.

In regard to the height of the Mexican volcanoes, there is no uncertainty. They have been carefully measured by Sonntag, whose barometrical observations agree with the trigonometrical ones of Humboldt, made more than fifty years before. According to Sonntag, Popocatapetl is 17,783 feet in height, and must, therefore, be allowed the honor of standing at the head of the mountains of the North American continent."

PROF. J. D. WHITNEY'S SURVEY OF CALIFORNIA-PROPOSED MAPS.-The California Geological Survey is likely soon to give us much more precise information respecting the physical geography of that state than can now be obtained from all other sources. The following extract from a communication to the California Academy by Prof. J. D. Whitney, the State Geologist, exhibits what has already been accomplished.

"California is covered by a vast net-work of mountain ranges, separated by comparatively narrow valleys, with the exception of those of the Sacramento and San Joaquin, which do not, together, cover more than one-fifteenth of the area of the State. The remaining fourteen-fifteenths may be called mountainous, as the valleys include but a small portion of its surface. Into this mountainous region no accurate surveys have ever been carried; even the General Land Office work stops at the base of the mountains. A few ranch lines have been run among the moderately elevated portions of the Coast Ranges; but, as a general thing, the genuine Mexican grants were limited to the plains.

Without considerable topographical work in connection with the geological survey we should, then, be entirely unable to carry on our geological work with any pretense to accuracy, as we could neither locate our observations nor make our descriptions of the country intelligible. The authority for doing something for the increase of the geographical knowledge of the State is found in the clause of the act authorizing the survey, which requires "proper maps" to accompany the reports.

What has been done, up to the present time, in this department may be briefly recapitulated as follows:

A series of maps, forty-nine in number, has been compiled by Mr. Hoffman from the original documents at the United States SurveyorGeneral's Office; the scale of these is half an inch to the mile. They contain a compilation of nearly all that is known at that office in regard to the geography of the State. The maps, as thus blocked out, have been used by us in the field, by filling in the topography wherever our route has laid.

The maps which have been or are now being prepared for publication are:

1st. A map of the vicinity of the Bay of San Francisco, on a scale of half an inch to the mile, four feet by three; it extends from near Santa Cruz on the south to Napa on the north, and from the Pacific to Corral Hollow, east and west. The area of land which it covers is 4,248 square miles, which is just twice that of the State of Delaware, and only lacks two hundred square miles of equalling that of Connecticut. As near as can be ascertained, it contains one third of the population of the State, and has about thirty inhabitants to the square mile-the average density of the population of California being but little over two to the square mile. This map, on which all the details of the topography are given, as minutely as the scale allows, is nearly completed, and will be soon ready for the engraver.

2d. A detailed map, on a scale of two inches to the mile, of the vicinity of Mount Diablo; this is about two and one-half by three feet in dimensions, and includes the most important coal mining district yet known to exist in the State. The map can be made ready for the engraver in a few days.

3d. A map of the Coast Ranges, from the Bay of Monterey south to Santa Barbara. It is about three feet by two and one-half in dimensions, is on a scale of six miles to the inch and embraces about 16,000 square miles of territory. To complete it will require about another year's work in the field with two sub-parties.

4th. Map of the Washoe silver-mining region-three and one-half by two and one-half feet in dimensions, on a scale of two inches to the mile -and extending over all the important mining ground of the district. This map is from an accurate trignometrical survey by V. Wackenreuder; it is nearly completed.

5th. Map of the Comstock Lode, on a scale of four hundred feet to the inch, completed.

6th. Map of the central portion of the Sierra Nevada; scale not yet determined on. Extensive surveys have been made by Mr. Wackenreuder for this part of the work, and these will be continued during the present

season.

Of the above mentioned maps, Nos. 1 and 2 will accompany the first volume of the Report. Nos. 4, 5, and probably 6, the second volume.

It is intended, if the survey is carried to completion, to construct a final map of the State on a scale of six miles to the inch, in nine sheets, each about three feet square.

In addition to the regular topographical work, an extensive series of barometrical observation has been made, for the determination of altitudes, some two hundred and fifty important points having been ascended and measured. The most interesting operation in this department was the determination of the height of Mount Shasta, which, by an elaborate series of observations, we found to be 14,440 feet above the sea level. This is the first of the lofty volcanic peaks of the Sierra Nevada which has been accurately measured.

In the department of geology proper, our explorations have extended over portions of forty of the forty-six counties into which the State is divided; and when it is remembered that the average size of a county is equal to half that of the State of Massachusetts, (California having just twenty-four times the area of that State,) some idea of the magnitude of our work may be obtained. The chain of the Sierra Nevada may be parallelized with that of the Alps for extent and average elevation; while the Coast Ranges are nearly as extensive as the Appalachian chain of mountains.

We have obtained a pretty clear idea of the general structure of the Coast Ranges from Los Angeles to Clear Lake; the vicinity of the Bay of San Francisco has been worked out in considerable detail, including all of San Francisco, San Mateo, Santa Clara, Alameda, Contra Costa, and Marin Counties, with portions of Santa Cruz, Solano, Napa, and Sonoma. Considerable field-work has been done in the Sierra Nevada, chiefly in the lower portion of the range between Mariposa and Shasta Counties. Our observations have also been extended to the Washoe Region, and we have received considerable collections of fossils from the Humboldt Mining District, (known by this name on the Pacific Coast, but designated on Warren's Map as the "West Humboldt River Range," and in longitude 118°) by which we have been able to fix the age of the formations in that region."

RECENT AUSTRALIAN EXPLORATIONS.-Some months have passed since we have made reference in these pages to the important researches which have been making to discover the physical structure and natural characteristics of the interior of Australia. From the Lond. Geog. Soc. Proceedings (iii, 82), to which we are indebted for so much information that illustrates the progress of British enterprise, we draw the following ex

tracts.

"1. Explorations from Adelaide across the Continent of Australia ; by J. McDOUALL STUART.-This expedition proceeded along the previous route until they reached the point attained by Mr. Stuart in 1861, from which he was obliged to retire in consequence of the inability of his small party to penetrate further.

The dense scrub that had in 1861 formed an insurmountable barrier was penetrated after six weeks' incessant labor, and the other side was reached in safety and without loss.

On getting into clear country again and taking observations, they found themselves in lat. 16° 40'. Ten miles further on, or lat. 16° 30', they struck on a large river, apparently a branch of the Roper River, which they followed down until its confluence with the main stream, known as the Roper River. They found that it took its source in some rocky and hilly land, through which they crossed several creeks running in a northeast direction, until they reached the table-land in lat. 13° 50′ and in long. 132° 30'. They crossed this table-land and came upon a large river with a strong current, running through well-grassed country, admirably adapted for grazing and agricultural purposes. The river ran in a northwest direction, and the party followed its course for a considerable distance, until in lat. 12° 50' and long. 131° 40′ it changed to due north. On this course they travelled for about 30 miles, and then struck due east for about 10 to 15 miles; after which due north to the seaport in Van Diemen Gulf, which was reached on the 24th of July, 1862; and on the following day they planted their flag on the beach amid great cheering from the party.

The point on the coast reached was a promontory marked on the Admiralty Charts as being 30 miles east of Cape Hotham.

The river, which they followed, ran about 40 miles parallel with a river marked on the map as the Adelaide, the difference in the longitude being only from 6 to 12 miles. Stuart passed through much good country, well fitted for agricultural and pastoral purposes. Leichhardt had previously seen this tract, and noticed it in terms not less favorable. Even in the scrub water seems to have been found in sufficient quantities to satisfy the wants of all the party, including the horses, obviating any necessity for carrying a supply from camp to camp beyond Newcastle Water.

They were not nearly so fortunate on the return route, being more than two whole days before they obtained a necessary supply the only occasion on which they were inconvenienced by its want.

Their provisions held out till the latter part of their journey, when they were compelled to sacrifice three of their horses for food.

Mr. Stuart met M'Kinlay at the Kapanda Station; and at the Adelaide Station Mr. Howitt's party were among the first to welcome him home after his laborious but successful mission.

2. Exploration of the Interior of Australia; by Mr. LANDSBOROugh. -Mr. Landsborough, who had previously (Proceedings, vol. vii, p. 5) explored southwesterly for 300 miles, started from the Gulf of Carpentaria on the 10th February, 1862, following the Leichhardt for some distance, and turning off near the falls in a direction E.S.E. over a grassy country. This terminated in some picturesque hills, among which it was thought that a sheep establishment would be well placed. Beyond the hills there was more wood and less pasture. The Flinders was crossed on the 19th, followed for some time, and finally left on the 1st March in lat. 20° 3'. Near Mounts Little and Brown the river is deep, and seems perennial. The country is probably thinly inhabited, as the

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