72 G. H. KNIBBS. 



streets should also be avoided. It may here be noted on the 

 other hand, that in an hexagonal radial system, if "ring-streets," 

 as they have been called, are used to connect the radial lines (e.g. 

 Fig. 5), there is a distinct advantage over a system of hexagons 

 of the same area, the mean distance of travel to the centre being 

 8 - 25% more for the latter, Ring and curved streets may conse- 

 quently be advantageously introduced, at any rate occasionally; 

 and there can be no doubt therefore that they should form, if not 

 a marked, at least a minor feature of any future design for a city. 



7. Cardinal direction of rectangular streets. — The cardinal direc- 

 tion of streets, and for the orientation of buildings, is a question 

 which must be studied in relation to the latitude of a site, and to 

 the particular purpose to which buildings are to be applied. 

 Between the tropics, the sun will occupy at some time of the year 

 and day all points of the compass : his northern aspect for the 

 whole year preponderating for places south of the equator, and 

 his southern for places north thereof. Since in that zone his 

 meridian altitude is great, and the meridian shadows are therefore 

 short, the merits of a particular aspect have to be decided on 

 somewhat different grounds to those which apply in temperate 

 regions, where, as we depart from the tropics, there is a great 

 disproportion between the whole lengths of the midsummer meri- 

 dian-shadow, and the similar shadow in midwinter, and where also 

 the sun at noon is not at one time north of the place of the observer, 

 and at another time south. 



With a view to more clearly illustrating the nature of solar 

 shadows on a horizontal tract of land, Fig. 7 has been prepared, 

 for the nearest 5th degree of latitude to that of this city (Sydney), 

 i.e., for latitude 35° S. The laws of position of the shadow of a 

 vertical line may be thus defined for the temperate zone. For any 

 one interval of time before or after apparent noon (i.e. the crossing 

 of the sun over the meridian of a place) the terminals of the shadows 

 on different days are points in a straight line which, produced, 

 passes through a point defined by drawing a line from the elevated 

 pole of the heavens through the top of the vertical line till it 



