It would be a mistake to infer from its geometric merits that the hexagonal was the only proper form of the radial system. We may often need a greater number of converging streets than six from one point. At the Arc de Triomphe in Paris there are no less than fourteen converging avenues, at the Place de la Bastille ten, at the Place de la Nation nine. At the Capitol in Washington there are eleven long converging streets, and eight and ten in other places in the same city. At Karlsruhe, in Germany, there are no less than eleven radial streets in about 120 degrees of arc, their directions all converging upon the Castle, Library, and Cabinet of Natural History.

4. Position of Radial Centres.---Radial centres may be described as points about which particular types of civic activity will tend to concentrate they may be the foci of political, administrative, commercial, or manufacturing energies, or of intellectual or aesthetic interest. Hence they must be on leading lines of communication, on the broadways of traffic, and consequently, also, the most careful regard must be paid in their selection, not only to the limitations imposed by the topographical features of the site, but also to those imposed by the positions of outlying centres and existing or potential roads and railways thereto. Similarly, strenuous care must be exercised as to their efficiency in times of peace and in times of war. Economy of effort in reaching industrial or other ends requires that activities having many points of contact, or frequent need of intercommunication, shall be so grouped as to reduce inter-communication itself to a minimum, and thus it happens that, in order to properly design a city, it becomes necessary in focussing its various energies to have throughout regard to convenience, efficiency, and artistic effect. Nothing short of an exact appreciation of the topographical adaptability of the site, and of the interdependence and mutual influence of different forms of civic activity, is sufficient for so localising the occupation of the city that its political, administrative, military and various other features, previously specified, shall be the best possible from every point of view.

Digressing for a moment from the general question, it may be said that, in mentioning the necessity for attention to our military needs, it may be remarked that this is a matter we are likely to treat too lightly. It has been, so far, our good fortune in this land never to have heard the horrid clamour of Bellona; nevertheless the experience of mankind (e.g., Paris in the last Franco-German war) shews how important the military provision is, and how bitterly we may rue inattention thereto. Hence, however much it may be disregarded so far as immediate necessities are concerned, ample provision for facilitating the mobilisation and despatch of troops, war material, etc., and for the defence of the city, must be made in the design, in recognition of the inevitable contingencies of at least the more remote future.

Among the several radial centres or focal points to be provided in the design, that at which Parliament will be housed--and round which the great departments of public administration should therefore be concentrated as a matter of convenience-will necessarily receive first attention as the grandest centre. For the accommodation of judiciary, commercial and industrial institutions, of a University and its affiliated colleges, of technical and high schools, of barracks, armouries, and other

provisions for the rapid mobilisation of troops, and also for sites for great public monuments and monumental buildings, other centres must be located in such a manner as best meets the practical needs of city life, and, at the same time, enhances the appearance of the city.

5. Other Systems of Streets.-As has already been stated, the radial system is unequivocally advantageous from every point of view. Reverting to the question of the best angle between the radial lines, it may be remarked that in a square divided by two diameters into four equal squares, and in a circle of equal area divided into six equal sections by three diameters, the total perimeter length in the latter case is only about 15 per cent. greater than in the former, while the mean perimeter distance from all points to the centre is 14 per cent. less that is, supposing the perimeter lines to represent streets, then the reduction of average distance to the centre is practically equal to the increase of street length necessary to obtain it. A little reflection will shew that the hexagonal radial system is, as previously stated, the best from this point of view, and involves the introduction of ring streets round the centre, something like those at Karlsruhe in Germany, or those in one quarter of New Orleans in America (e.g., St. Charles Avenue.) If, however, for the ring streets straight ones are substituted, the iteration of the hexagonal system leads to a division of the entire area into a series of triangles approximately equilateral in form. This scheme possesses the marked advantage of making the greatest distance of travel from any one point to any other never more than 15.47 per cent. greater than the direct distance between the two, while in the rectangular system of streets the distance may be as much as 41.42 per cent. greater. (Hence the ratio of advantage is 115.47: 141.42 = 100 : 122.47.) While shewing that the rectangular system, pure and simple, ought never to be accepted, this fact does not shew that that system may not be beneficially combined with the hexagonal or any other form of the radial system. In travelling about a city set out on the rectangular system, there is a distinctly better sense of orientation than where its streets are irregular, and it has always been felt that from the point of view of building construction it has much to commend it. Ancient Antioch, with its magnificent "golden" street, about 4 miles in length, and 200 feet in width, was substantially rectangular in design, and so also are the majority of cities. It is almost self-evident that a combination of the two systems practically secures the advantages of each, and this is the merit of L'Enfant's design for the Capital City of the United States of America. (See Fig. I.)

A radial rectangular system like that of Washington is possible, however, only where the ground is sensibly level, and to attempt to apply it in its integrity to any site without regard to the topographical features of the latter, would be to wholly misconceive the problem of design. Cities cannot be designed on a general pattern. Configuration of surface not only necessitates the setting out of streets in such positions as will give the best gradients, it also modifies the design in respect of the localisation of its centres, and in respect of its general scheme from the standpoints of aesthetics and hygiene, a matter to which we shall later refer at greater length.

We may say at once, therefore, that the radial system, either with or without its cross or connecting streets in polygonal or spider's-web form, or in ring form, and the rectangular system may be combined in any way whatsoever suggested by the conformation of the ground, or by the necessities of localising the centres with respect to convenience or artistic effort. And similarly curved streets, or even streets of zigzag form, may properly be introduced, or rather should be introduced, wherever the resulting gradients shew them to be advantageous. Not only may curved streets be employed where they are practically necessitated, they may even be introduced where traffic is only moderate in quantity, for the relief of an unartistic uniformity, provided that the element of gradient is thereby improved.

6. Cardinal Direction of Rectangular Streets.-In the temperate zones the sun's direction for six months of the year is never south of an east-and-west line, a fact shewing that the north-and-south and castand-west directions for the streets in a rectangular system is an error. Where topographical features do not interfere, the directions making angles of 45 with the principal cardinal points are evidently the best so far as the theory of solar light is concerned, Ottawa and Montreal are laid out conformably to this idea.

In latitude 35° South-the nearest fifth degree to the latitude of Sydney-the following proportions obtain between the meridian shadows at the summer solstice, the equinoxes, and the winter solstice, viz., the length of the sun's shadow at noon is respectively, t, fo, and § of the height of the supposed vertical object casting the shadow on a horizontal plane. The sun is east or west at the following intervals of time before or after apparent noon on the several dates mentioned,

The north-east and north-west faces have at all times 8 hours of continous direct sunlight; the south-east and south-west faces from 6 to 13 hours, or a mean of 4 hours, the duration of direct sunlight thereon at the equinoxes. Fuller information on this matter will be found in my paper previously referred to. It has to be remembered that the adoption of directions making angles of 45° with the true north-andsouth and east-and-west lines will often be greatly modified by the surface configuration. The theory of the best position is to be taken as a guide, not as an inflexible rule admitting of no variation.

7. Width, Grade, Cross-section, and Location of Streets.-In dealing with the characteristics of streets in a capital city, the first principle that may be laid down is that the asthetic requirements may be regarded as of commanding importance, and should, therefore, be given prominence in the general idea, while utilitarian considerations should be subordinated to the last possible degree consistent with the fact that the general arrangements must be really practicable. Although there is no inveterate opposition between artistic effect and convenience, there must to some extent be a sacrifice of one to the other. Thus in respect of the element of width, economy of construction and maintenance, and mere convenience in the conduct of business would suggest the narrowest width of street that would avoid intense congestion of vehicular and pedestrian traffic, while from the sanitary and aesthetic points of view wide streets are preferable, since they are less dangerous, and are both healthier and more beautiful.

Dealing with actual dimensions, and commencing at the lower limit, it may be affirmed that lanes of less than 10 metres width are very undesirable. Unimportant streets, so situated that they can never become of importance, might be designed with widths of from 20 to 25 metres. Streets of moderate importance likely to require tramways, cycle paths, central walks and so on, would be satisfied by a width of from 30 to 40 metres; while still wider streets, set out with avenues of trees, flower-beds, etc., might be of any width from 50 to 75 metres. For the purpose of comparison it might be mentioned that the streets of Washington are from about 24 to 36 metres, and the avenues about 36 to 49 metres. The usual cross section of roadway with raised footpaths should hold good for the narrowest streets only. In those of medium width a row of fine foliage trees on each side next to the footwalk would constitute the usual feature. In streets where there is little traffic, as for example those in the residential quarters of the city, strips forming garden or grass plots, graced with shrubs of various kinds, might well form a feature. To obtain variety, a somewhat wider streat could have a centre-line or lines of ornamental trees with, or without, footwalks, or a cycle path, etc. The widest streets would allow of side-walks, bounded by rows of trees, or strips of garden, and a triple-central avenue of fine proportions with double footwalks, and still leave ample room for two roads for tramway or vehicular traffic. Cycle and motor paths-already referred to-would always be so located as to involve a minimum of interference with other forms of locomotion.

Touching the question of the limits of street gradient, it may be observed that it must necessarily be sufficient to carry off surface drainage its lowest limit would, therefore, be %. For vehicular

traffic no severer grade than 10% should be allowed, and it is hardly necessary to say that of alternative possible designs, that which, other things being equal, secures the lightest grades throughout, especially in the streets which carry the heaviest and greatest amount of traffic, is the better.

The interdependence of topographical features, types of occupation, and character of street, in a city intended to be ideally healthy and beautiful, requires that the study of the design should be exhaustive. Every possible variation should be systematically analysed by a comparative method, for it is only in this way that the best result can be achieved.

The following are the main principles of location. For leading lines of heavy traffic light grades are required, and widths proportionate to its ultimate magnitude. Special regard must be paid to adequate provision for all future contingencies at such points of congestion as depôts and freight yards of all kinds, railway stations, and similar places. As before said, provision necessary for the mobilisation and despatch of troops, war material, etc., must also be borne in mind, whatever opinion obtain as to the needlessness of this in the near future.

With respect to residential streets, gradient is of less importance, it being merely necessary that the general character of the street should harmonise with the class of residences adjoining. Where they are to be palatial, the streets should possess a collateral magnificence, while the streets in localities populated by the poorer classes must of course be less pretentious in design, though they, too, may well be made picturesque with foliage trees.

8. Engineering Features of Streets.-The necessity for some official control of the localisation of the different classes of occupation, which a regard for the general appearance and welfare of a capital city not only justifies but imperatively demands, permits its development to proceed on lines that obviate frequent changes in the constructional features of the streets; for these can all be thoroughly considered at the outset. The mains, conduits, tunnels, etc., required for water, gas, electric, or various forms of power-supply, for sewerage systems, for telephone and telegraphic services, or for underground communication of any sort, can be located so as to involve the minimum disturbance of traffic, and the least expense for maintenance and repair; and the characteristic breaking up of, and injury to well-constructed streets, in order to reach such mains and conduits, can thereby be rendered an unknown element We pay dearly for want of foresight in municipal arrangements, in the constructional features of streets. In future city-design, the opportunity undoubtedly exists for avoiding that continual waste of resource, which, turned to advantage in more lavishly equipping public institutions, and in making the city ornate, can be so much better expended. An exhaustive consideration of the treatment of each street in regard to the necessity for tram or railways, is also necessary to ensure that the construction is developed on lines that avoids waste through the undertaking of various useless works, or injury to necessary ones. It will be a wise economy also to make the foundations of all streets thoroughly, and in no way to stint the means for so doing.