[4] Professor Henrici, Report on Planimeters (64th meeting of the British Association, Oxford, 1894); J. Tennant, “The Planimeter” (Engineering, xlv. 1903).
[5] H. Wagner’s Lehrbuch (Hanover, 1908, pp. 241-252) refers to numerous authorities who deal fully with the whole question of measurement.
[6] Kienzl of Leoben in 1891 had invented a similar apparatus which he called a Relief Pantograph (Zeitschrift, Vienna Geog. Soc. 1891).
[7] M. Fiorini, Erd- und Himmelsgloben, frei bearbeitet von S. Günther (Leipzig, 1895).
[8] Jahrb. des polytechn. Instituts in Wien, vol. xv.
[9] Compare the maps of [Europe], [Asia], &c., in this work.
[10] The great majority of the maps in this work are made by this process.
[11] Lepsius, Urkundenbuch, Pl. XXII.
[12] These Colchians certainly were not Egyptians. The maps referred to may have been Assyrian.
[13] We are indebted to Strabo for nearly all we know about Greek cartographers anterior to Ptolemy, for none of their maps has been preserved.