Rung Ho! by Talbot Mundy — Read

Even in darkness lime and sand / Will blend to make up mortar. / Two by two would equal four / Under a bucket of water.

NOW it may seem unimaginable that two Europeans could be cooped in Howrah, not under physical restraint, and yet not able to communicate with any one who could render them assistance. It was the case, though, and not by any means an isolated case. The policy of the British Government, once established in India, was and always has been not to occupy an inch of extra territory until compelled by circumstances.