The return of the British expedition from Tibet was evidently the opportunity of a century for the investigation of this unexplored country. We had gained the hitherto inaccessible base, and were provided with supplies and transport on the spot; we had no opposition to expect from the Tibetans, who were naturally eager to help us out of the country by whatever road we chose, and had promised to send officials with us to their frontier at Gyala Sendong, who would forage for us and try to impress the villagers into our service. The hostile tribes beyond the frontier were not so likely to resist an expedition moving south to their homes after a successful campaign as a force entering their country from our Indian frontier. In the latter case they would naturally be more suspicious of designs on their independence. The distance from Lhasa to Assam was variously estimated from 500 to 700 miles. I think the calculations were influenced, perhaps unconsciously, by sympathy with, or aversion from, the enterprise.
The Shapés, it is true, though they promised to help us if we were determined on it, advised us emphatically not to go by the Tsangpo route. They said that the natives of their own outlying provinces were bandits and cut-throats, practically independent of the Lhasa Government, while the savages beyond the frontier were dangerous people who obeyed no laws. The Shapés' notions as to the course of the river were most vague. When questioned, they said there was a legend that it disappeared into a hole in the earth. The country near its mouth was inhabited by savages, who went about unclothed, and fed on monkeys and reptiles. It was rumoured that they were horned like animals, and that mothers did not know their own children. But this they could not vouch for.
It was believed that tracks of a kind existed from village to village all along the route, but these, of course, after a time would become impracticable for pack transport. The mules would have to be abandoned, and sent back to Gyantse by our guides, or presented to the Tibetan officials who accompanied us. Then we were to proceed by forced marches through the jungle, with coolie transport if obtainable; if not, each man was to carry rice for a few days. The distance from the Tibet frontier to Sadiya is not great, and the unexplored country is reckoned not to be more than seven stages. The force would bivouac, and, if their advance were resisted, would confine themselves solely to defensive tactics. In case of opposition, the greatest difficulty would be the care of the wounded, as each invalid would need four carriers. Thus, a few casualties would reduce enormously the fighting strength of the escort.