Cahill-Keyes Octant X-Y Coordinates & Segment Lengths

Cahill 1909

Go back to Gene Keyes home page

Cahill-Keyes M-layout world map silhouette including Antarctica

Cahill-Keyes 1975

Cahill-Keyes Octant Graticule

X-Y Coordinates
and Segment Lengths
(scaffold triangle and perimeter only)
1/10,000,000 and 1/1,000,000

cc by Gene Keyes 1980-05-01; 2010-02-05

Here is another installment of my drafting notes for the
Cahill-Keyes “Real-World” map. See also
Notes on Re-designing B.J.S. Cahill's Butterfly World Map
Notes on Scaling Cahill and Cahill-Keyes Maps
Photos of the Cahill-Keyes Megamap Prototypes (esp. Fig. 4)

Numbers are stated as coordinates on a millimeter grid on a sheet that is 1,000 x 1,200 mm for a 1/10,000,000 template. Note that line 0 starts 100 mm above the bottom of the grid.

* This table also serves for drafting a 1/1,000,000 octant template, which covers an assembly of 62 square-meter panels (diagrammed elsewhere). In that case, use the extra digit in the (*) columns after X and Y respectively, ("Panel" column refers to coding of the 62 square-meter version,)

	*Point*	Panel	X	*	decimal	Y	*	decimal
Scaffold Triangle
base midpoint (altitude foot)	G		`0500`	`0`	`0000`	`0200`	`0`	`0000`
Vertexes:
	M		`0`			`1066`	`0`	`2541`
	N		`1000`	`0`	`0000`	`0488`	`6`	`7513`
	P	J 42	`0`			`-0088`	`6`	`7513`

(Altitude reference points: not to draw; for corroboration):
	C		`0500`	`0`	`0000`	`0777`	`3`	`5026`
	K		`0`			`0488`	`6`	`7513`
	S		`0333`	`3`	`3333`	`0488`	`6`	`7513`
Octant Perimeter Itself
Vertexes
*Starting point*	A		`0047`	`0`	`0000`	`0984`	`6`	`1902`
	E		`0906`	`0`	`0000`	`0488`	`6`	`7513`
	I		`0047`	`0`	`0000`	`-0007`	`2`	`6873`
	Q		`0953`	`0`	`0000`	`0407`	`2`	`6873`
Joints
	B		`0222`	`4`	`0639`	`0937`	`6`	`1902`
	D		`0777`	`5`	`9361`	`0617`	`0`	`8152`
	F		`0777`	`5`	`9361`	`0360`	`2`	`6874`
	H	H 50	`0222`	`4`	`0639`	`0039`	`7`	`3126`
	J		`0`			`0168`	`1`	`3765`
	L		`0`			`0809`	`2`	`1263`
	R		`1000`	`0`	`0000`	`0231`	`8`	`6325`

Segment Lengths, in mm			mm	*	decimal
Scaffold Triangle
MN, etc.: sides			`1154`	`7`	`0053`
MG, etc.: altitude(s)			`1000`	`0`	`0000`
MB, DN, etc.: vertex sides			`256`	`8`	`1278`
EN, etc.: altitude indent			`94`	`0`	`0000`
MD, etc.: vertex to 2nd indent			`897`	`8`	`8773`
Octant Perimeter Itself
AG etc.: internal altitude			`906`	`0`	`0000`
AB, etc.: each end-segment			`181`	`5`	`9406`
BD, etc.: each mid-segment			`641`	`0`	`7498`
ABCDE, etc. each 3-segment side			`1004`	`2`	`6307`

* For a 1/10,000,000 map, read first column of digits only. For a 1/1.000.000 map, append (*) column's digit. Other decimals are for optional precision: e.g., if a 1/100,000 map, append first digit from four-place decimal column; for a 1/10,000 map, append the second; etc.

Go back to B.J.S. Cahill Resource Page
Go back to Gene Keyes home page