NEW YORK, SEPTEMBER 10, 1904. 
$1 PER YEAR 
Yol. LXIIl. "No. 2850. 
A TALK ABOUT CEMENT. 
Making Artificial Stone. 
POR TLAND CEMENT is composed of sand, lime 
and clay ground together wet in certain proportions, then 
dried and baked in a kiln until nearly the melting point; 
then this clinker is reduced by grinding to a very fine 
powder. It has the property of taking up and combining 
with a certain proportion of water, and in a very short 
time “setting'’ into a solid mass. After it has once “set, ’ 
no addition of water will soften it again, and it" mixed 
with sand or broken stone before the setting process 
commences, the whole mass is united into a solid body 
by the cement. This product is called concrete. Al¬ 
though cements were used by the ancient Roman build¬ 
ers long before the Christian Era, the arc appears to 
have been lost and practically rediscovered by a brick- 
maker in Leeds, England, about the year 1824. While 
making bricks from the sediment washed from a lime¬ 
stone turnpike, he found when burned hard and pow¬ 
dered they would harden again into a stone. lie took 
out a patent, and called this cement “Portland,” from 
the resemblance to the Portland limestone, the favorite 
building stone of that country. From 
this humble beginning a world-wide in¬ 
dustry has grown and millions of dollars 
arc invested in its manufacture. An 
abundant supply of the raw material 
and cheaper methods have brought down 
the cost until cement construction bids 
fair to supersede either clay or wood 
with the most enduring building mate¬ 
rial known. It is very doubtful whether 
the Roman cements were equal to our 
own American product, as we know that 
Pliny, an eminent writer of that time, 
complained of their quality in the 
strongest terms; yet, there are not a few 
structures standing now more than 
2,000 years old in which this cement was 
used. A notable specimen remains in 
the Pantheon of Rome. The dome of 
this building, 142 feet in diameter, rest¬ 
ing on walls 25 feet in thickness, is a 
solid arch of concrete. There are many 
impure limestones, which, when calcined, 
produce natural cements, such as Rosen- 
dale, etc., but Portland cement is a 
purely chemical product, requiring a 
high degree of skill and experience to 
produce. It is said that a variation of 
one-half of one per cent will often materially lessen the 
value of the product. Abundant capital is needed to 
manufacture it in a large way, and we are proud to 
acknowledge that America now leads the world in quan¬ 
tity as well as quality. 
CONCRETE is a name given to a solid substance 
artificially compounded of such loose materials as sand, 
gravel or crushed stone united by cement. In order to 
construct such a solid, we first must provide for filling 
up all the open spaces. A cubic foot of crushed stone 
contains about one-third of its area of such voids, and 
will take up about one third of its bulk of Sand without 
any increase in dimension, requiring still one-third more 
of cement and water to expel all the air and make it a 
solid body. This compound, when sufficiently seasoned, 
is called concrete, and while the proportions of each in¬ 
gredient may be varied, or sand alone used, the best 
results are obtained when a mixture of coarse and fine 
materials are used together. There are two methods of 
making concrete, known as the wet and the dry. In the 
first sufficient water is added at once to dissolve the 
cement. This is the ordinary method of concrete ma¬ 
sonry, and needs no further explanation. The dry 
method varies in this respect, that only enough water 
is added at first to dampen the compound, so that it 
can be pressed in molds and formed into desired shapes. 
These forms can then be lifted from the molds and 
are afterwards kept in a moist condition for some days, 
until sufficient water is absorbed to set the cement. 
The advantages gained by the dry method are very 
great, as it enables the operator to use the same mold 
continually and rapidly duplicating his product. While 
each process has its advocates, it is the opinion of most 
civil engineers that tamping or pressing makes the most 
solid concrete. The mechanical advantages, however, 
gained by the dry method, are so great that it must 
necessarily always be popular, and in fact the present 
growing interest in concrete construction is in a great 
measure attributed to the introduction of this process 
in the manufacture of hollow building blocks. Concrete 
made in the wet way requires to stand in the mold-form 
24 to 36 hours before it can be moved, while the blocks 
made by dry tamping process can be repeated every 
few minutes in the same machine. 
RULES FOR CONCRETE MAKING.—In the 
manufacture of concrete, four rules must be strictly 
followed or partial failure, if not entire failure, will re¬ 
sult : 1. All materials used must be free from clay, 
loam, or vegetable matter, and only a standard make of 
Portland cement used. 2. The thorough mixture of 
all the ingredients in the dry condition before any water 
is added, in order that each particle of stone or sand 
shall receive a dust covering of cement. 3. Never al¬ 
low the blocks to dry out for at least one week after 
they have been removed from the machine, but keep 
them as much as possible out of the sun and air and 
sprinkle every day with a hose or watering pot. 4. Not 
to have the blocks moved or even jarred for at least a 
week after they are taken from the machine and set 
aside to season. The reason for this is that the cementa¬ 
tion of all these ingredients into a solid body is a pro¬ 
cess of crystallization of the cement, and it is necessary 
that their surface shall be clean and all coated with a 
thin covering of it, for every minute particle of cement 
changes with the condition of the water to a crystalline 
product, and attaches itself to the sand and stone, 
uniting them into a solid mass. Since the slightest 
movement detaches these minute crystals and arrests 
their formation, the concrete is weakened to that ex¬ 
tent. The time of rest varies from 24 to 36 hours, ac¬ 
cording to the grade of the cement and the amount of 
water used, some cement acting more rapidly than others. 
'This is what is called the initial or first setting of the 
concrete. The crystallization now having taken place, 
a certain length of time is necessary for them to harden, 
for at first formation they are very tender and brittle, 
but have the remarkable property of growing harder 
from day to day and year to year without contraction. 
Fig. 295 shows how blocks of “artificial stone” or con¬ 
crete are made. The machine consists of a mold or 
form, into which the concrete is firmly packed. The 
machine can then be opened so that the block is taken 
out and set aside for hardening. 
SOWING WHEAT AFTER CORN. 
The Preparation of the Same. 
NO SUMMER FALLOW.—In the corn belt, where 
the corn ripens in time for wheat to be sown, and get a 
start before freezing weather, the Summer fallow is 
going out of date, and wheat follows corn. To suc¬ 
ceed with this plan, the land should not have more than 
one crop of corn taken off, after plowing sod before 
being sown to wheat. For wheat, after corn, a three- 
year rotation of corn, wheat and clover is best. Then, 
by the use of commercial fertilizer on the wheat, the 
farmer, if his land is well drained naturally or arti¬ 
ficially, can expect profitable crops of wheat. By this 
plan, one plowing of the land gives the 
three crops of corn, wheat and clover. 
Corn stubble should never be plowed 
for wheat. It is a useless and costly ex¬ 
pense, and besides takes up too much 
time in getting the land ready. Some 
farmers think the corn should be re¬ 
moved from the land; this is too costly, 
and besides is very heavy work. 
ROLLER ON CORN STUBS.—It is 
also thought by those inexperienced that 
the corn stubs should be cut off close to 
the ground before trying to work the 
land; this also is unnecessary. If they 
are heavy and tall, the easiest way to get 
them out of the way is to run a roller 
over them as soon after the corn is in 
the shock as possible. This is easily 
and rapidly done with the modern steel 
roller, eight feet long. If the stubs are 
quite green many of them will break off 
close to the top of the ground, unless 
the land is very mellow, in which case 
they will be bent over, many of them 
having the roots turned up. Drive the 
roller around lands the size desired to 
drill about, when sowing commences. 
Then follow with a disk harrow, driving 
in the same direction ; straddle every corn row with the 
team and harrow; this will give two cultivations. The 
harrow should not be set to cut over two inches deep. 
Follow the disk harrow with a drag harrow, driving 
in the same direction. This will smooth down the land, 
and pull up the loose stubs, and may be, if the driver 
allows, drag them into piles. Some of them will have 
large quantities of soil attached to their roots. If left 
this way, they will—to some extent—clog the drill. To 
have them out of the way, roll the land again. This 
will crush the soil out of the roots, leaving them almost 
bare. This is not too much work for the good of the 
land, and in nearly all cases will make an excellent 
seed bed. Nearly all farmers make a mistake in sow¬ 
ing wheat after corn, in that they do not give the land 
enough work before sow-ing; the aim mainly seems to be 
quantity sown, rather than quality of work done. 
FUR THER PREPARATION.—If level cultivation 
has been given the corn, the seed bed for the wheat can 
be made almost perfect. If the corn has had ridge 
culture, the seed bed will be too deep if leveled and 
worked down to an even depth. In the preparation of 
the land as described here, the object in working the 
tools in the same direction is to have the stubs all to 
lean in the direction the drill is driven, the drill fol¬ 
lowing in the direction the other tools have been 
MAKING BUILDING BLOCKS OF CONCRETE. Fig. 295. 
