THE THEORY OF CITY DESIGN. 67 



lengths : secondly that there is only half the number of acute 

 angles (45°), so that the 'octagonal-radial' is distinctly preferable 

 to the 'rectangular-diagonal' system. The most striking advantage 

 is seen however in (5). Table (I.) shews that in respect of travel- 

 distance it is practically equal to the diagonal system, and but 

 little inferior to the octagonal-radial system ; while in respect to 

 street-length it is vastly superior to either : and still farther, it 

 .gives altogether better angles, viz. 6 angles of 60° instead of 8 

 angles of 45°. We conclude therefore, that in order to secure the 

 greatest advantage as to distance of travel, in a radial scheme of 

 streets, the angles between the radiating lines should be approxi- 

 mately 60°, and that the cross-streets should be approximately 

 .symmetrical with respect to the centre : and further that such 

 arrangement is to be preferred to the rectangular, so far at least 

 as shortness of communication is concerned. This is very strik- 

 ingly brought out on comparing (5) with (I). The total length 

 of streets is increased only 15-|%, while the mean distance of travel 

 is reduced as much as 14%; in other words the reduction of dis- 

 tance of travel is practically identical with the increase of street- 

 length! The radial system, pure and simple, has however some 

 limitations which will be later considered, it is sufficiently clear 

 that there should be points from which streets should radiate in 

 all directions. 



4. Position of Radial Centres. — The first point to be decided in 

 elaborating a design for the streets of a city, is the position of 

 what may be called its chief radial-centres, and its main lines of 

 street. A concrete idea of what is meant by chief radial centres, 

 would be reached by regarding such centres as the Capitol and the 

 White House at Washington; or the Arc de Triomphe at Paris, 

 between the Avenue de la Grande Armee and the Avenue des 

 Champs Elysees. They may be defined as the centres round which 

 ■either particular types of, or even general activity, will tend to 

 ■concentrate, or they may be centres of aesthetic or intellectual 

 interest, and it is obvious therefore that they should, as a rule, 

 lie on the leading lines of communication between one place and 



