Albuquerque daily citizen. [volume] (Albuquerque, N.M.) 1895-1903, 1902-06-07

proportioned with reference TO the diff
ferent loads and stresses to which they
were to be subjected. AS time passed,
the needs of man became more COM
pick. Because of social advantages
and for mis- mutual protection villages,
then cities. were formed; and for
means of communication and COM
merce railroads from place to place,
and bridges to cross rivers we're nee
essary. Mans conception of materials
both natural and artificial-and their
uses, broadened, and for every in
crease in size and complexity of struc-
lures erected, consideration of availa-
BILE material was necessary.
Granite must be selected because of
its durability; marble, for polish; and
wood. because of it's a~daptability and
the ease with which it can be worked.
In no case could the question of
strength be left out. and the question
of e~conomizing in the amount of ma
terial used is of primary Importance.
1t is under the stress of quite mod
ern necessity, however, that the prob
lem of using materials to the greatest
advantage in securing strength has
come to be of primary Importance in
the mind of the designer, and today in
the erection of structures, and ma
chimes. no matter what other objects
are in view, the designer must consid-
er to what straining actions they are to
he subjected, the amount of material
necessary to resist this strain, the SAT-
est material to use. and the best dispo-
sition of It. The simplest method of
ascertaining the strength-say of a
bridge or boiler-is to apply to 1t a
greater testing load than 1t will be eX-
pected to carry when in actual use. Be-
fore a bridge is opened to general
traffic it is tested by running loads, or
a train of locomotives over its whole
length. and before steam IS placed in
a boiler il is put to a hydro-static test
greater than the indicated gauge read
ing of the boiler. This method of test
ing though in use today as a guarantee
of safety, does not give the engineer a
true knowledge of what the bridge will
actually stand; nor o it make him
acquainted with the different physical
and chemical properties of the mater
ials used. In other words, the infor-
nation acquired by this class of test
ing does not give all the specific infor-
nation desired. 1t is the desire for
this specific information to aid in con-
struction that has led engineers to
otuhy small opCNihttho ~ "
mine what effect different mixtures or
varying compositions will have IN the
strength of materials. and the ma
chimes used to determine these
strengths are called testing machines
There are two objects in view in any
test-one is scientific, the other COM
mercial. In scientific testing the OBJ
ject is to determine physical constants,
to find out the density, the elastic
limit, the yield point, and the coeffi-
cient of elasticity of a material.
The object of commercial testing is
to determine the quality of a material
used in any special construction. For
this purpose samples are taken from
different portions of the stock, and
tested by methods approaching the
scientific as nearly az practicable.
Whether the quality meets the de-
mands of the specification is deter
mined by testing. 1t is because of this
fact that a great variety of testing ma
chimes are coming into more general
use. The consumer tests the product
to see il 1t meets the required de-
mands;; the manufacturer tests the
raw materials. In this way higher
tandards in construction works are es-.
tablished. Thus, a practical knowledge
VI the DTODtTtltS VI IHdltIldlb rs es-
sential to the mechanical and civil en-
gineers of today. On their Judgment
| depends the welfare of both consumer
and producer. Even the public at
large are concerned; for the safety of
| the structure built is also in their
hands.
The object of this thesis Is to test q
few OF the building materials used in
New Mexico; such as wood, brick,
rock. cement and others. The tests,
about eighty in all. were performed on
an Olsen testing machine of 60 900
pounds capacity. In order to give an
idea of how these tests were carried
out a portion of that section on tests
of bricks will be given.
During late years there has been a
decided increase in the amount OF
brick used in building construction.
due no doubt to the fact that they are
practically indestructible. either by the
action of the weather, the presence Of
acids in the atmosphere, or by fire.
Moreover, they can be made any size.
are light, and consequently easily
handled. Bricks are made of a MKT
ure of clay and sand, or a silicate of
| aluminium. This sometimes contains
| an admixture of oxide of iron and the
c~arbonates of lime and magnesia. The
presence of sand prevents cracking.
shrinking, and warping; but experience
shows that over % per cent of sand In
a brick ruins it's cohesive power. and
makes iL brittle. Both the oxide of
iron, and carbonate of lime act as a
huX which fuses the constituents of
the brick together; but an excess OF
either will make the brick run and lose
its shape. The quantity of iron also
has a great influence on the color OF
the brick.
Bricks are either hand or machine
made. and in all cases, as the tests
showed, the machine made bricks are
by far the superior.
The different bricks tested were OBJ
tanned from kilns in this locality. as
well as both machine and hand made
brick from Albuquerque and La
Vegas. An individual test of each
brick was made to determine both its
crushing strength and it's absorption.