THE GARDENERS' CHRONICLE OF AMERICA. 



133 



walks, when once built, will be nearly 20 miles in length, 

 and the boulevards lYi miles. 



The waterway e.xcavations between Lake Calhoun and 

 Lake of the Isles amounted to 92,000 cubic yards and 

 cost $13,340; between Lake of the Isles and Cedar Lake, 

 <S.3,000 cubic yards costing $14,200, and between Cedar 

 l-ake and IJrownie Lake, 9,000 cubic yards costing 

 $3, .300. The total amount of material moved, therefore, 

 is 186,000 cubic yards at a total cost of $31,040. 



E.xtensive dredging operations have also been carried 

 out on Lake Calhoun and Cedar Lake, the material con- 

 sisting mostly of gravel and sand, which was used for 

 boulevard and beach construction. At Lake Calhoun 

 473.000 cubic yards of material were so delivered, 100,000 

 cubic yanls of which were needed for a large bathing 

 beach. 



At Cedar Lake 100,000 cubic \ards were dredged for 

 boulevard construction. 



The Lake of the Isles dredging ainounted to 419,000 

 cubic yards. The total amount of dredging done on all 

 lakes and channels is 1,17S,000 cubic vards, at a total 

 e.xpen.se of $167,000. 



In addition to that a bath house, costing $6.3,000, has 

 been built at Lake Calhoun, which accommodates 1,700 

 persons at a time, and has an attendance of about 

 300,000 per season. 



The entire cost of all improvements, exclusive of land 

 acquisitions, carried out within the district of the four 

 lakes since 1907, amounts to $350,000, and while this is a 

 large sum of money, it is a com[)aratively small expense 

 considering the value of these properties to the city as a 

 whole and to its people. A large amount of work remains 

 to be done to bring those park lands to the desired state 

 of development contemplated, and large additional ex- 

 penditures are necessary to complete the work. Time 

 will bring the means and see it all dune, and the con- 

 census of the generation that will see it all an accom- 

 plished fact, will be that the money and efforts spent 

 were a sound and splendid investment, which will bear 

 compound interest for all time to come. 



The series of articles on Pacific Coast Park S\stems 

 ill be renewed in the .\])ril number. 



Construction Problems in Road Building 



By Linn White, Illinois. 



It is hardly true that the construction of every road or 

 the paving of every street is an original problem in itself, 

 requiring the collection of data and the independent de- 

 termination of dimensions. P'or the sake of uniformit)', 

 if for no other reason, some standards must be adopted 

 and rules tDrmulatcd that are somewhat arbitrary and 

 empirical. Put, in spite of this necessity, the design of a 

 road — width, depth and crown, as well as longitudinal 

 grades and character of wearing surface — should be 

 adajJted to the traffic, soil, climate, drainage, etc., of the 

 liarticular locality in which it is situated. 



Widths of roadways are governed primarily b\- the 

 extent and character of traffic. A highway ma\' be de- 

 signed for the ]")assage of onh' two veliicles with no pro- 



"Kxtracls from a naper read befure the .American Road Huiiders' Asso- 

 ciation, at Ciiicago. liy the Chief Engineer, South Park Commissioners, 

 Chicago, ni. 



vision for standing next the curl), in which case the paved 

 width can scarcely be less than 16 feet. As the import- 

 ance of the highway increases and vehicles at higher 

 speed use it and more provision must be made for stand- 

 ing room, foot passengers, etc., the width should increase 

 t.i' 18, 20 or 24 feet. 



In a comparison between the ])aAcd width of streets 

 and roads, note should be taken of the fact that in streets 

 the whole width, including gutters, is generally paved and 

 used by the traffic, whereas in speaking of the paved 

 width of a road as, say. 18 feet, the earth shoulders and 

 gutters are not included — an additional width on each side 

 of perhaps 3 feet, bringing the total width of such a road 

 u]i to 28 feet. As an instance of the difference that may 

 I)roi)erly be made in the width of a street because of stop- 

 l>ing and stantling vehicles next the curb tiie following in- 

 stance may be cited. (_)ne of the principal business thor- 

 oughfares leading out from the central portion of Chi- 

 cago borders imblic jiark territory for more than a mile. 

 A double-track electric car line was on the street, and on 



