The sound of musical instruments, chiefly of drums, is a phenomenon of another class, and is really produced in certain situations among sandhills when the sand is disturbed. [See supra.] A very striking account of a phenomenon of this kind regarded as supernatural is given by Friar Odoric, whose experience I fancy I have traced to the Reg Ruwan or “Flowing Sand” north of Kabul.  Besides this celebrated example, which has been described also by the Emperor Baber, I have noted that equally well-known one of the Jibal Nakus, or “Hill of the Bell,” in the Sinai Desert; Wadi Hamade, in the vicinity of the same Desert; the Jibal-ul-Thabul, or “Hill of the Drums,” between Medina and Mecca; one on the Island of Eigg, in the Hebrides, discovered by Hugh Miller; one among the Medanos or Sandhills of Arequipa, described to me by Mr. C. Markham; the Bramador or rumbling mountain of Tarapaca; one in hills between the Ulba and the Irtish, in the vicinity of the Altai, called the Almanac Hills, because the sounds are supposed to prognosticate weather-changes; and a remarkable example near Kolberg on the shore of Pomerania.  A Chinese narrative of the 10th century mentions the phenomenon as known near Kwachau, on the eastern border of the Lop Desert, under the name of the “Singing Sands”; and Sir F. Goldsmid has recently made us acquainted with a second Reg Ruwan, on a hill near the Perso-Afghan frontier, a little to the north of Sistan.  The place is frequented in pilgrimage. (See Cathay, pp. ccxliv. 156, 398; Ritter, II. 204; Aus der Natur, Leipzig, No. 47 [of 1868], p. 752; Remusat, H. de Khotan, p. 74; Proc.  R. G. S. XVII. 91.)

NOTE 3.—­[We learn from Joseph Martin, quoted by Grenard, p. 170 (who met this unfortunate French traveller at Khotan, on his way from Peking to Marghelan, where he died), that from Shachau to Abdal, on the Lob-nor, there are twelve days of desert, sandy only during the first two days, stony afterwards.  Occasionally a little grass is to be found for the camels; water is to be found everywhere.  M. Bonin went from Shachau to the north-west towards the Kara-nor, then to the west, but lack of water compelled him to go back to Shachau.  Along this road, every five lis, are to be found towers built with clay, and about 30 feet high, abandoned by the Chinese, who do not seem to have kept a remembrance of them in the country; this route seems to be a continuation of the Kan Suh Imperial highway.  A wall now destroyed connected these towers together.  “There is no doubt,” writes M. Bonin, “that all these remains are those of the great route, vainly sought after till now, which, under the Han Dynasty, ran to China through Bactria.  Pamir, Eastern Turkestan, the Desert of Gobi, and Kan Suh:  it is in part the route followed by Marco Polo, when he went from Charchan to Shachau, by the city of Lob.”  The route of the Han has been also looked for, more to the south, and it was believed that it was the