Peter Alexeivitch Kropotkin,
Encyclopædia Britannica, Ninth Edition
(1888)
“ Beyond this narrow strip of irrigated laud begins the desert,— the Kara-kum,—which extends from the mountains of Khorasan to Lake Aral and the Ust-Urt, and from the Caspian to the Amu, interrupted only by the oases of Merv and Tejefi. It appears, how ever, that the terrible shifting sands blown into barkhans, or elongated hills, sometimes 50 and 60 feet in height, are grouped chiefly in the west, where the country has more recently emerged from the sea. ”
