Hedges, Bench and Street Grade Engineer, Department of Public Works, Chicago, Ill., gives the following data regarding quant.i.ties and cost.

The materials required for each monument are: 1.78 cu. yd. crushed stone, 0.6 cu. yd. torpedo sand, 1 bbls. cement, 60 ft. B. M. lumber, one 24-in. copper rod, one top and cover. A gang consisting of 1 foreman, 4 laborers and 2 teams construct from one to three monuments per day, the average number being two per 8-hour day. In 1906 the average cost of the monuments was $24.12 each, based on above material and labor charges.

[Ill.u.s.tration: Fig. 305.--Base for Wooden Pole.]

[Ill.u.s.tration: Fig. 306.--Mile Post, Chicago & Eastern Illinois Ry.]

~POLE BASE.~--Figure 305 shows a concrete base for transmission line poles invented by Mr. M. H. Murray, of Bakersfield, Cal., and used by the Power Transit & Light Co. of that city. These bases are molded and shipped to the work ready for placing. They weigh about 420 lbs. each.

One base requires 37 lbs. of 2-in. steel bar, 40 lbs. of Portland cement, 3 cu. ft. of broken stone or gravel and enough sand to fill the form or mold, which is 1010 ins. by 4 ft. Unskilled labor is employed in the molding and two men can mold ten bases per 8-hour day. The cost of molding is as follows per base:

2 men at $2 per day $0.40 Brace irons per set 2.50 1-9 cu. yd. stone at $4.05 0.45 40 lbs. cement at 1 cts. 0.60 Sand 0.15 ----- Total cost $4.10

Two men at $2 per day each set five bases in eight hours, making the cost of setting 80 cts. per base. The bases were sunk to a depth of 3 ft. 3 ins. In many cases they were placed under poles without interrupting service by sawing off the pole, dropping it into the ground, placing the new base and setting the sawed-off pole on it and bolting up the straps.

~MILE POST, CHICAGO & EASTERN ILLINOIS R. R.~--The dimensions of the post are shown by Fig. 306. Each post weighs 498 lbs. They are made when other concrete work is being done. The form is laid flat, with the molds for the letters on the bottom, and bottom and sides are plastered with mortar, which is backed up with a 1-1-2 stone concrete. The cost of the post is given as follows:

barrel of cement at $2 $0.50 267 lbs. crushed stone 0.01 133 lbs. sand 0.01 1-1/3 hours labor at 15 cts. 0.20 1/3 hour carpenter changing letters at 25 cts. 0.08 Coloring cement 0.02 ----- Total $0.82

~BONDING NEW CONCRETE TO OLD.~--Concrete which has set hard has a surface skin or glaze to which fresh concrete will not adhere strongly unless special effort is made to perfect the bond. Various ways of doing this are practiced. The most common is to clean the hardened surface from all loose material and give it a thorough wash of cement grout against which the fresh concrete is deposited and rammed before the grout has had time to set. Washing the old surface with a hose or scrubbing it with a brush and water improves the bond, as does also the hard tamping of the concrete immediately over the joint. Mortar may be used in place of grout. The thorough cleansing of the surface is, however, quite as essential as the bonding coat, in fact in the opinion of the authors it is more essential. As a rule, a good enough joint for ordinary purposes can be got by tamping the fresh concrete directly against the old concrete, without grout or mortar coating, if the surface of the latter is thoroughly cleaned by scrubbing and flushing. The secret of securing a good bond between fresh concrete and concrete that has set lies largely in getting rid of the glaze skin and the slime and dust which forms on it. Washing will go far toward doing this. The glaze skin can be removed entirely by acid solutions, but the acid wash must be flushed free from the surface before placing the fresh concrete. Ransomite, made by the Ransome Concrete Machinery Co., Dunellen, N. J., is a prepared acid wash which to the authors" knowledge has given excellent success in a number of cases. The glaze coat can also be removed by picking the hardened surface, but the picking should be followed by washing to remove all loose chips and dust.

~DIMENSIONS AND CAPACITIES OF MIXERS.~--In planning plant lay-outs it is often desirable to know the sizes, capacities, etc., of various mixers in order to make preliminary estimates. Tables XXII to x.x.xIII give these data for a number of the more commonly employed machines. The Eureka, the Advanced and the Scheiffler mixers are continuous mixers and the others are batch mixers.

Table XXII--Sizes, Capacities and Weights of Advanced Mixers.

Cement Machinery Co., Jackson, Mich.

Height ground to hopper top 3" 6"

Width over all 3" 6"

Length over all on trucks 10" 6"

Capacity per hour, cu. yds. 25 to 75 Horsepower, engine 2 Weight: On trucks, without power, lbs. 1,700 On trucks, steam engine 2,000 On trucks, gas engine 2,200 On trucks, steam engine and boiler 2,500

Table XXIII--Sizes, Capacities and Weights of Scheiffler Proportioning Mixers. The Hartwick Machinery Co., Jackson, Mich.

Mixer Number. No. 2. No. 2. No. 3.

Dimensions of hopper, ins. 5533 5333 6040 Height, from ground to top of hopper, ins. 43 43 48 Width over all on trucks, ins. 46 46 46 Length over all on trucks, ins. 126 126 132 Hourly capacity in cubic yards 5-6 8 12-15 Horsepower required, gasoline engine 2 3 4 Horsepower required, steam engine. 3 4 Weights: On trucks, without power, lbs. 2,400 2,900 3,300 On trucks, gasoline engine, lbs. 3,000 3,600 4,500 On trucks, steam engine, lbs. 2,800 3,330 4,000 On trucks, steam engine and boiler, lbs. 3,500 3,700 4,800

Table XXIV--Sizes, Capacities and Weights of Eureka Mixers.

Eureka Machine Co., Lansing, Mich.

----------------------------------------------------------------- | | | | Mixer Number | No. 81 | No. 82 | No. 83 | -------------------------------|----------|----------|----------| _ | | | | | Sand | 18"25" | | | Size hoppers, ins. | Cement | 17"25" | do | do | |_ Stone | 30"25" | | | Height, ground to hopper top | 49" | 49" | 49" | Width over all on trucks | 40" | 40" | 40" | Length over all on trucks | 12"-9" | 10"-0" | 10"-0" | Capacity per hour, cu. yds. | 10 to 18 | 10 to 18 | 10 to 18 | Engine horsepower | 3 stm. | 3 stm. | 3 gas | Boiler horsepower | 4 | | | Weight on trucks, no power | 1,980 | 1,980 | 1,980 | Weight trucks steam engine | 2,800 | | | Weight trucks gas engine | | | 2,300 | Weight trucks, eng. and boiler | 3,000 | | | -------------------------------|----------|----------|----------|

----------------------------------------------------------------- | | | Mixer Number | No. 84 | No. 25 | No. 23 -------------------------------|------------|----------|---------- _ | | | | Sand | 18"25" | 18"25" | 18"25"

Size hoppers, ins. | Cement | 17"25" | 17"25" | 17"25"

|_ Stone | 30"25" | | Height, ground to hopper top | 49" | 49" | 49"

Width over all on trucks | 40" | 40" | 40"

Length over all on trucks | 10"-0" | 8"-0" | 8"-0"

Capacity per hour, cu. yds. | 10 to 18 | 10 to 18 | 2 to 4 Engine horsepower | 3 el. motr | Pulley. | Hand.

Boiler horsepower | | | Weight on trucks, no power | 1,980 | 1,400 | 1,400 Weight trucks steam engine | | | Weight trucks gas engine | | | Weight trucks, eng. and boiler | | | -------------------------------|------------|----------|----------

Table XXV--Sizes, Capacities and Weights of Snell Mixers.

R. Z. Snell Mfg. Co., South Bend, Ind.

Mixer Number. No. 0. No. 1. No. 2. No. 3.

Size batch, cu. ft. 3 7 11 24 Capacity per hour, cu. yds. 2 5 8 20 Speed revs. per min. 30 30 25 19 Weight on Skids: With pulley, lbs. 480 800 900 2,000 With engine, lbs. 800 1,550 2,050 3,500 With eng. and boiler, lbs. 2,170 2,900 4,000 Weight on Wheels: With engine, lbs. 1,100 2,200 3,450 4,700 With engine and boiler, lbs. 3,570 4,750 5,200 Engine: Size cylinder, ins. 46 34 45 56 Rated horsepower 1 4 5 6 Boiler: Size, ins. 2460 2660 3060 Rated horsepower 5 6 8 Outside dimensions on skids 2"9"4" 3"4"5"6" 4"6" 6"9"

Total height on skids 3"8" 4"6" 5" 5"6"

Table XXVI--Sizes, Capacities and Horsepower of Ransome Mixers.

Ransome Concrete Machinery Co., Dunellen, N. J.

Mixer number. No. 1. No. 2. No. 3. No. 4.

Size batch, cu. ft. 10 to 14 20 30 40 Capacity per hr., cu. yds. 10 20 30 40 Speed, Revs. per min. 16 15 14 14 Weight on Skids: Pulley or gear, lbs. 3,300 3,650 5,900 7,400 With engine, lbs. 4,600 5,050 7,700 9,250 With engine and boiler, lbs. 6,450 8,700 12,200 14,700 Weight on Wheels: With engine, lbs. 5,100 5,550 8,200 9,750 With engine and boiler, lbs. 6,950 9,200 12,700 15,000 Engines: Size cylinder, ins. 66 77 88 99 Rated horsepower 7 10 14 20 Boiler: Size, ins. 3669 4275 4287 4893 Rated horsepower 10 15 20 30

Table XXVII--Sizes, Capacities and Horsepowers of Chicago Improved Cube Mixers. Munic.i.p.al Engineering and Contracting Co., Chicago, Ill.

Mixer No. No. No. No. No. No.

number. "Handy." 6. 11. 17. 22. 33. 64.

Size batch, cu. ft. 2 6 11 17 22 33 64 Capacity per hr., cu. yds. 5 13 24 40 50 70 120 Speed, revs. per min. 24 20 18 17 16 15 12 Weight on Skids: Pulley or gear, lbs. 1,000 1,900 2,800 5,000 7,000 9,600 19,000 With engine, lbs. 2,500 3,600 6,100 8,200 12,000 With eng. and boiler, lbs. 3,100 4,300 7,800 10,000 16,000 Weight on Wheels: With engine, lbs. 1,400 3,200 4,500 7,100 9,500 15,000 With eng. and boiler, lbs. 4,000 6,000 8,800 10,300 17,000 Engine: Size cylinder, ins. 44 66 67 78 89 Rated horsepower 2 3 6 8 12 15 30 Boiler, rated horsepower 4 8 10 15 18 35 Width over all 4"-5" 5"-10" 7"-1" 7"-8" 8"-6" 9"-8"

Length over all 4"-10" 6"-9" 8"-0" 8"-10" 10"-2" 13"-6"

Height bot. sill to charging hopper 3"-4" 3"-5" 3"-10" 4"-7" 5"-0" 5"-9"

Additional height on wheels 9-7/8" 1"-5-1/8" 1"-5-1/8" 6-3/8" 5"

Table XXVIII--Sizes, Capacities and Horsepowers of Cropp Mixers.

A. J. Cropp, Concrete Machinery, Chicago, Ill.

Mixer number. No. 0. No. 1. No. 2. No. 3. No. 4.

Size batch, cu. ft. 7 to 8 10 13 16 20 Cap. per hr., cu. yds. 15 20 25 30 40 Speed, revs. per min. 12 10 10 10 10 Weight on Skids: With engine, lbs. 1,375 1,650 1,700 1,975 2,100 With eng. and boiler, lbs. 2,575 2,950 3,000 3,775 3,900 Weight on Wheels: With engine, lbs. 1,775 2,050 2,200 2,475 2,600 With eng. and boiler, lbs. 2,900 3,350 3,400 4,250 4,350 Engine: Size cylinder, ins. 44 55 55 66 66 Rated horsepower 3 5 5 7 7 Boiler: Size inside 24"4" 24"6" 24"6" 30"6" 30"6"

Rated horsepower 4 6 6 9 9 Out. dimensions on skids 40" 40" 40" 48" 48"

Total height 50" 56" 56" 56" 62"

Height fr. ground on trucks: Charging, ins. 20 20 20 20 20 Discharging, ins. 30 30 30 30 30

TABLE XXIX--SIZES, CAPACITIES AND HORSEPOWERS OF CHICAGO CONCRETE MIXERS.

Chicago Concrete Machinery Co., Chicago, Ill.

Number of mixer. No. 00. No. 0. No. 1. No. 2.

Standard charge in cu. ft. cement 1 1 2 " " Sand 1 2 4 8 " " stone 3 5 8 16 Total unmixed batch in cu. ft 5 8 13 26 Mixed concrete per batch, loose in cu. ft. 3 6 9 18 Cubic yards of unmixed material per hour, 45 batches per hour 8 14 21 42 Cubic yards of mixed concrete per hour, 45 batches per hour 6 10 15 30 Minimum horsepower required 2 4 6 8 Revolutions of driving pulley per min 200 190 185 170 Revolutions of drum per min 20 18 15 13 Diameter and face of driving pulley 203 204 245 286 Weight: On skids with pulley, lbs. 1,550 2,150 2,900 4,850 On truck with pulley or gears, lbs. 1,800 2,550 3,500 5,150 On skids with st. engine only, lbs. ... 2,400 3,400 4,600 On truck with st. engine only ... 2,900 4,000 5,300 On skids with st. eng. and boiler, lbs. ... 2,800 4,700 6,000 On truck with st. eng. and boiler, lbs. 2,400 4,200 5,750 7,850 On skids with gasoline engine, lbs. 2,000 3,500 5,000 6,500 On truck with gasoline engine, lbs. 2,400 4,300 5,800 7,800

TABLE x.x.x--SIZES, CAPACITIES AND HORSEPOWERS OF KOEHRING MIXERS.

Koehring Machine Co., Milwaukee, Wis.

Mixer number. No. 0-B. No. 1-B. No. 2-B. No. 3-B.

Capacity per charge, in cu. ft 7 11 22 27 Capacity per hour in cu. yds 7 14 25 30 Horsepower, steam engine 4 6 8 10 Horsepower, steam boiler 5 8 10 14 Horsepower, gasoline engine 4 6 10 12 Horsepower, electric motor 5 6 7 10 Speed of drum 20 17 15 15 Speed of intermediate shaft 132 108 75 75 Weight of mixer on skids 1,800 2,800 5,200 5,500 Weight of mixer on skids, with steam eng. 2,300 3,550 6,500 7,000 Weight of mixer on skids, with steam engine and boiler 3,300 5,000 8,000 9,300 Weight of mixer on skids, gasoline engine and housing 3,000 4,400 7,500 8,600 Weight of trucks with pole 400 600 850 950 Weight of automatic loading bucket complete 500 700 1,000 1,100 Weight of mixing through complete 200 250 400 400