Published topographic atlas sheets, arranged by States-Continued.

a Yellowstone National Park sheet includes Canyon, Gallatin, Lake, and Shoshone sheets.

Bull. 227-04-13

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Published topographic atlas sheets, arranged by States-Continued.

a Yellowstone National Park sheet includes Canyon, Gallatin, Lake, and Shoshone sheets.

GENERAL, COMBINED, SPECIAL, AND FORESTRY MAIS.

In addition to the topographic atlas sheets, the Survey has prepared and printed certain general maps needed in its work; maps made by combining certain topographic atlas sheets; special maps covering areas of peculiar economic importance; forestry maps.

a The Survey has issued a sheet of "conventional signs" used on its topographic maps; price, 5 cents a single sheet; 2 cents each in lots of 100 or more.

b No wholesale rate for Crater Lake sheet.

The map sheets represent a great variety of topographic features, and with the aid of descriptive text they can be used to illustrate topographic forms. This has led to the projection of an educational series of topographic folios, for use wherever geography is taught in high schools, academies, and colleges. Of this series three folios have been issued, viz:

Folios Nos. 1 and 2, each entitled "Physiographic Types," by Henry Gannett, and Folio No. 3, entitled "Physical Geography of the Texas Region, by Robert T. Hill. The prices of the three published folios are as follows: Folio No. 1, twentyfive cents; Folio No. 2, twenty-five cents; Folio No. 3, fifty cents.