Friday, June 4, 2010

Calculated center of Ripper's pentagram, no change

Calculating midpoint of pentagram (intersection of line from Mitre to Durward, and line from Henriques to midpoint between pentagram's top vertices) and bearing from St. Paul's (east end) to center of pentagram:

Mary Jane Kelly (Dorsett) 51.518661,-0.075107

Anne Chapman (Hanbury) 51.520447,-0.072564

Calculated midpoint between Dorsett & Hanbury: 51.519444, -0.073889 (midpoint calculation is automatically performed when using the bearing-calculator I've been using to calculate bearings)

Line A):

from: Elizabeth Stride (Henriques St) 51.513769,-0.065576

to: Midpoint between Dorsett & Hanbury: 51.519444, -0.073889

Calculated bearing from Henriques to Midpoint: 317.652222

Line B):

from:Catherine Eddowes (Mitre Sq) 51.513728,-0.078042

to: Mary Ann Nichols (Buck's/Durward) 51.520036,-0.060401

Calculated bearing from Mitre to Buck's: 60.110556

Intersection (using calculator further down on same page as bearing-calculator):

Calculated intersection (center of pentagram):51.516667, -0.069722

Calculated bearing from St. Paul's to center: 80.720000 (9.28 above east-west axis)

(This is essentially identical to the angle I calculated using the midpoint which I determined by drawing the lines of interest in Google Earth.)