Sometimes, among the ice-clad peaks of the giant ranges of the Himalayas, they crossed snowy passes fourteen thousand feet above the sea, and did not neglect to throw a stone upon the _obos_--the cairns that pious and superstitious travellers erect to propitiate the spirits of the passes. Sometimes the path led under beautiful cliffs of pure white crystalline limestone that in the brilliant sunlight shone like the finest marble. Often they journeyed through a lovely land of gently-sloping hills, of grassy uplands, of deep valleys giving delightful vistas of snow-clad mountains far away. They walked through pinewoods, through forests of maple, silver fir, and larch, and miles of huge bushes of flowering rhododendrons. They toiled up a rough and stony track over bare and desolate land that was an old moraine and under moraine terraces one above another, forming giant spurs of the rugged hills. There were dark and fearsome ravines, so deep that they could scarcely hear the roar of the foaming torrents rushing among the great boulders below as they crossed on swaying suspension bridges of iron chains. These had been built hundreds of years before by long-forgotten Chinese engineers. Three chains on one level supported the bamboo or plank footway, while one on either side served as a hand-rail, and a bamboo or grass lattice-work between them and the roadbearers hid from sight the deep gorge below. Often these bridges were only of ropes of twisted withes or grass and swung and swayed in terrifying fashion with the motion of the traveller. There were broad rivers over the eddying, swirling waters of which strong cantilever bridges of stout wooden beams were pushed out from the steep banks. Truly a beautiful land Bhutan, at its loveliest perhaps in spring, when the hills and upland meadows where the yaks graze, ten thousand feet above the sea, blaze with the mingled colours of anemones blue and white, of yellow pansies and mauve and white irises, of large white roses and small yellow ones, of giant yellow primulas with six tiers of flowers, when the oaks and the chestnuts are clothed in young green, and the apricot, pear and orange trees are in bloom, when large and lovely blossoms cover that little-known tree that the Bhutanese call _chape_, when the bright green of the young grass runs up to the white snowfields. The woods are full of a pretty ground orchid, beautiful trailing blossoms of others droop from the boughs of the great trees, and on the magnesium limestone hills one of the rarest orchids grows in profusion.