If, for a reason other than distance, Adelaide is 2114 miles away and Alexandria is 1359 and if Hobart is 2148 miles away whilst Malta is 1258, how far is Stockholm?
I think that the numbers are expressing longitude as a time east of GMT - i.e. there are 360 degrees/24hrs in one full rotation of the earth so 1 degree = 15 mins. So , with Greenwich's longitude of 0 giving 1200 , Stockholm's longitude of 18.05 E would give 1312