1 Dilloway , A. J.: Cartographic Solution of Great Circle Problems, Jour. Roy. Aer. Soc., Vol. 46, 1942, pp. 4–31.CrossRefGoogle Scholar

2 For a general treatment of air-route problems from the geographical aspect, see the discussion, The Geography of Post-War Air Routes, Geog. Jour., Vol. 103, 1944, pp. 89–100 Google Scholar; and for a magnificently exhaustive treatment from the technological standpoint, see Warner, E. P.: Post-War Transport Aircraft, Jour. Roy. Aer. Soc., Vol. 47, 1943, pp. 186–254.Google Scholar

3 Feeder routes branching north and south from the main great circle routes may of course ’ help to cancel out this criticism.

4 The treatment of this question which follows is an extension of the author's part in a discussion on the Map of the Pacific. See Geog. Jour., Vol. 100, 1942, pp. 65–72.CrossRefGoogle Scholar

5 For a full treatment, see Dilloway, Op. cit., Jour. Roy. Aer. Soc., 1942.

6 Dilloway, op. cit.

7 R. Buckminster Fuller has produced a gnomonic world map by dividing the surface of the sphere into fourteen segments formed by four intersecting great circles, and projecting these as eight equilateral triangles and six isquares which can be combined in any order. See R. Buckminster Fuller: Geography, Fluid, American Neptune, Vol. 4, 1944, pp. 119–136.Google Scholar

8 Maurer, H.: Ebene Kugelbilder, Petermann's Geog. Mitt., Erg. 221, 1935.Google Scholar

9 Fisher, Irving: A World Map on a Regular Icosahedron by Gnomonic Projection, Geog. Rev., Vol. 33, 1943, pp. 605–619.CrossRefGoogle Scholar

10 Hinks, A. R.: Maps of the World on an Oblique Mercator Projection, Geog. Jour., Vol. 95, 1940, pp. 381–383 CrossRefGoogle Scholar; Map Projections and Sun Compasses—III. More World Maps on Oblique Mercator Projections, Geog. Jour., Vol. 97, 1941, pp. 353-356; and see also in The Geography of Post-War Air Routes, pp. 93-95.

11 Miller, O. M.: Notes on Cylindrical World Map Projections, Geog. Rev., Vol. 32, 1942, pp. 424–430.CrossRefGoogle Scholar

12 Op. cit., pp. 68-69.

13 L. Driencourt and J. Laborde: Traité des Projections des Cartes Géographiques (4 Vols.), Hermann, Paris, 1932. Air maps are treated in Vol. 2, pp. 97-105.

14 Weems, P. V. H.: Marine Navigation, D. Van Nostrand Co., New York, 1940, pp. 24–26, 114–118.Google Scholar

15 Tonta, L.: Notes on Nautical Cartography, Hydrogr. Rev., Vol. 6, No. 2, 1929, pp. 53–65 Google Scholar. This paper was preceded by two others on the subject of polar navigation: A New Type of Polar Chart, Hydrogr. Rev., Vol. 5, No. 2, 1928, pp. 51-60; Notes and Tables on Polar Cartography, Hydrogr. Rev., Vol. 6, No. 1, 1929, pp. 83-110. Tonta suggests the use of a transverse Mercator projection for polar navigation.

16 Best visualised as the difference between the bearings included by a great circle which intersects the two meridians at a given latitude.

17 Although they are ignored in practice, the angular errors inherent in a particular map introduce an additional factor into corrections for true bearing.

18 Young, A. E.: Some Investigations in the Theory of Map Projections (Technical Series No. 1), Royal Geographical Society, 1920, pp. 40–41.Google Scholar

19 Hinks, A. R. (in Map Projections and Sun Compasses)—V. Murdoch's Third Projection. Geog. Jonr., Vol. 97, 1941, pp. 358–62.Google Scholar

20 Tonta, L., op. cit., Vol. 6, No. 1, 1929, pp. 88–89.Google Scholar

21 This statement is intended to cover ranges of latitude up to some 15° from the central parallel.

22 Tonta, L., op. cit., Vol. 6, No. 1, 1929, pp. 90–94.Google Scholar

23 Tonta, E., op. cit., Vol. 6, No. 2, 1929, pp. 60-62Google Scholar. With reference to this question of loxodromic distance, the present writer has constructed a scale giving rhumb-line distances in statute miles from arguments of bearing (between 15° and 74°) and difference of latitude.

24 Apparently Kahn's system was first outlined in a note presented at a meeting of the Academy of Sciences, Paris, on Feb. 20th, 1928, and recorded in Publication No. 8. See also Kahn, L.: Sur Une Extension de la Projection de Mercator: Les Nouvelles Cartes Aériennes. Académie de Marine, Communications et Memoires, Tome 8, 1929.Google Scholar

25 For a good example of this type of map in simple cylindrical projection, see Sir C. Arden-Close (in Map Projections and Sun Compasses)—I. An Oblique Rectangular Cylindrical Projection, Geog. Jour., Vol. 97, 1941, pp. 349-50.

26 Similarly, oblique polyconic projections offer no particular advantages over cylindrical types.

27 Poole, H.: A Map Projection for the England-Australia Air Route, Geog. Jour., Vol. 86, 1935, pp. 446–48.CrossRefGoogle Scholar

28 Dilloway, op. cit., Jour. Roy. Aer. Soc., 1942.

29 Herrick, Samuel: Grid Navigation, Geog. Rev., Vol. 34, 1944, pp. 436–56.CrossRefGoogle Scholar

30 A general treatment of certain aspects of the subject, including a rather optimistic tabulation of savings in great circle distance, is given by Plischke, Elmer: Trans-Arctic Aviation, Econ. Geog., Vol. 19, 1943, pp. 283–91.CrossRefGoogle Scholar

31 The true centre, established according to the conventions of “centrography,” is located near Nantes, in France. A good general treatment of this and various other centres (all much farther removed from London) is given by Raisz, Erwin: Our Lopsided Earth, Jour. of Geog., Vol. 43, 1944, pp. 81–89.Google Scholar

32 An international series on the scale of 1: 2,000,000 should be well suited to the new range of world flying. It is at these scales that the “grid” method is seen to best advantage.