After some difficulty I found the remains of a broad path that divided into two; one of them led to a second ruined temple, fully a mile off, and the other I followed to a grove, in which was a gigantic chait; it was a beautiful lane throughout, bordered with bamboo, brambles, gay-flowered _Melastomaceæ_ like hedge-roses, and scarlet _Erythrina_: there were many old mendongs and chaits on the way, which I was always careful to leave on the right hand in passing, such being the rule among Boodhists, the same which ordains that the praying-cylinder or “Mani” be made to revolve in a direction against the sun’s motion. This great chait is the largest in Sikkim; it is called “Nirbogong,” and appears to be fully forty feet high; facing it is a stone altar about fifteen feet long and four broad, and behind this again is a very curious erection called “Song-boom,” used for burning juniper as incense; it resembles a small smelting furnace, and consists of an elongated conical stone building eight feet high, raised on a single block; it is hollow, and divided into three stories or chambers; in the lower of which is a door, by which fuel is placed inside, and the smoke ascending through holes in the upper slabs, escapes by lateral openings from the top compartment. These structures are said to be common in Tibet, but I saw no other in Sikkim. During my stay at Yoksun, the weather was very cold, especially at night, considering the elevation (5,600 feet): the mean temperature was 39°, the extremes being 19·2° and 60°; and even at 8 a.m. the thermometer, laid on the frosty grass, stood at 20°; temperatures which are rare at Dorjiling, 1,500 feet higher. I could not but regard with surprise such half tropical genera as perennial-leaved vines, _Saccharum, Erythrina,_ large bamboos, _Osbeckia_ and cultivated millet, resisting such low temperatures.[116] [116] This is no doubt due to the temperature of the soil being always high: I did not sink a thermometer at Yoksun, but from observations taken at similar elevations, the temperature of the earth, at three feet depth, may be assumed to be 55°. On the 14th January I left Yoksun for the lake and temples of Catsuperri, the former of which is by much the largest in Sikkim. After a steep descent of 1800 feet, we reached the Ratong, where its bed is only 3,790 feet above the sea; it is here a turbulent stream, twelve yards across, with the usual features of gravel terraces, huge boulders of gneiss and some of the same rock _in situ,_ striking north-east. Some idea of its velocity may be formed from the descent it makes from the foot of Mon Lepcha, where the elevation of its bed was 7,150 feet, giving a fall of 3,350 feet in only ten miles.