188 



ARBORICULTURE 



Cement Concrete as a Substitute for Wood in Constructions 



Inventive genius has been active dur- 

 ing several years past, seeking for some 

 substitute for wood, as advancing prices 

 of lumber, with greater scarcity, has 

 given fair warning of approaching famine 

 in American timber. 



For many years wood was almost the 

 only material used for houses, bridges 

 and structures of every kind, because it 

 was the most abundant, and easily attain- 

 able at low cost in nearly every locality: 

 but conditions have changed; wood is 

 no longer abundant, and must be trans- 

 ported thousands of miles in man)' 

 instances, while prices have doubled and 

 trebled within a brief period. 



On the other hand, the manufacture of 

 Portland cement has grown to mammoth 

 proportions, while the abundance and 

 cheapness of the minerals entering into 

 its composition, together with the general 

 abundance of gravel, crushed stone, sand 

 and water, for making concrete mortar, 

 makes this an inexpensive material which 

 in many cases has taken the place of 

 wood. 



Besides, unless protected from the 

 elements, wood is of comparatively short 

 duration, while concrete soon becomes 

 as firm as the natural rocks and will last 

 for centuries. 



FOUNDATIONS, CULVERTS AND BRIDGES 



In railway construction and repairs, 

 concrete is being used in lieu of natural 

 stone, for all foundations, retaining walls 

 and many culverts, some of which are 

 of size approaching small bridges. 



In parks and on roadways quite long 

 spans of bridges are built of reinforced 

 concrete, where formerly wood alone 

 was used. 



CONCRETE BUILDINGS 



It is interesting to note the evolution 

 in house construction since the settle- 

 ment of the new world. From the rude 

 cabins of the pioneers, built of round 

 logs, the ends notched in for strength, 

 with blocks of wood or stone used for 

 chinking, to fill the spaces between the 



logs, having mud plastered upon these 

 chinks; immense broad fireplaces to take 

 logs for fuel, floors of puncheons or logs 

 split in twain, the flat upper side hewed 

 smooth, roof covered with clapboards, 

 the pioneer saw mills supplying but 

 limited quantity of lumber at first. 



As the numbers and capacity of the 

 mills increased, boards and dimension 

 stuff afforded the frame buildings, which 

 were improved and made more comforta- 

 ble as time passed on. 



Then brick became common, although 

 not entirely supplanting the frame 

 wooden building. 



A year or two since iron and steel were 

 in general use for many purposes of 

 building in the large cities, and it was 

 predicted that these metals would entirely 

 supplant wood for house construction. 

 But the supply of iron is growing less 

 with the immense drain upon the mineral 

 beds, and there will be few buildings 

 constructed of iron, except as it is used 

 to reinforce concrete, and in the sky- 

 scrapers to bind the walls together. 



To-day cement concrete enters largely 

 into the construction of dwellings, either 

 in the foundations or in hollow concrete 

 blocks for the superstructure. 



Sixty years ago. Fowler, a noted 

 educator of New York, published direc- 

 tions and plans for farm houses, barns, 

 and numerous buildings were thus erected 

 in various portions of the United States. 



But waterlime or portland -cement is 

 very far superior to the mortar made 

 from carbonate of lime. 



The objection to concrete walls for 

 houses was the dampness of the walls, 

 but that seems to have been overcome 

 by the hollow blocks, which have large 

 air spaces within the walls. 



The blocks are usually 8x8x16 inches, 

 equivalent to the space occupied by 

 twelve bricks; their cost varies accord- 

 ing to abundance of materials, sand, 

 gravel or crushed stone, and distance 

 which these articles must be transported; 

 probably the average cost is ten cents 

 per block. Their manufacture is easily 



