ABSTRACT
The total for the day’s march, together with any other discreet observations, had somehow to be logged somewhere safe from prying eyes. It was here that the prayer-wheel, with its copper cylinder, proved invaluable. For concealed in this, in place of the usual hand-written scroll of prayers, was a roll of blank paper. This served as a logbook, which could easily be got at by removing the top of the cylinder, and some of which are still preserved in the Indian State Archives. Then there was the problem of a compass, for the Pundit was required to take regular bearings as he journeyed. Montgomerie decided to conceal this in the lid of the prayer-wheel. Thermometers, which were needed for calculating altitudes, were hidden in the tops of pilgrims’ staves. Mercury, essential for setting an artificial horizon when taking sextant readings, was hidden in cowrie shells and poured out into a pilgrim’s begging bowl when required. Concealed pockets were added to the Pundits’ clothing, and false bottoms, in which sextants could be hidden, were built into the chests which most native travellers carried. All this work was carried out in the Survey of India’s workshops at Dehra Dun under Montgomerie’s supervision.
