After having laid down these varied lines in the outline described, I determined to check and confirm its accuracy by recommencing the survey on a new plan, viz. trigonometrically. My parties were again despatched to resume their labours over fields now familiar to them. They commenced from points whose positions were fixed (and my knowledge enabled me to give a series of such), from each of which, as a centre, they collected every radiating route to every town within the distance of twenty miles. The points selected were generally such as to approach equilateral [7] triangles; and although to digest the information became a severe toil, the method will appear, even to the casual observer, one which must throw out its own errors; for these lines crossed in every direction, and consequently corrected each other. By such means did I work my way in those unknown tracts, and the result is in part before the reader. I say, in part; for my health compels me reluctantly to leave out much which could be combined from ten folios of journeys extending throughout these regions. =The Author’s Map.=—In 1815, as before stated, an outline map containing all the information thus obtained, and which the subsequent crisis rendered of essential importance, was presented by me to the Governor-General of India. Upon the very eve of the war I constructed and presented another, of the greater portion of Malwa, to which it appeared expedient to confine the operations against the Pindaris. The material feature in this small map was the general position of the Vindhya mountains, the sources and course of every river originating thence, and the passes in this chain, an object of primary importance. The boundaries of the various countries in this tract were likewise defined, and it became essentially useful in the subsequent dismemberment of the Peshwa’s dominions. In the construction of this map I had many fixed points, both of Dr. Hunter’s and my own, to work from; and it is gratifying to observe that though several measured lines have since been run through this space, not only the general, but often the identical features of mine have been preserved in the maps since given to the world. As considerable improvement has been made by several measured lines through this tract, and many positions affixed by a scientific and zealous geographer, I have had no hesitation in incorporating a small portion of this improved geography in the map now presented.[1.17]