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W. & L. E. GURLEY, TROY, N. Y.
Makers of Standard Weights and Measures and Testing Equipment

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Scale Journal

Published on the 10th of every month by the Scale Journal Publishing Company,

230 S. La Salle Street, Chicago, Ill.

J. A. SCHMITZ, Editor
C. A. BRIGGS, Associate Editor

SUBSCRIPTIONS $2.00 per year in the United States, Mexico and Canada, and $2.50 for the United Kingdom, the Continent of Europe, Australia, and other countries in the Universal Postal t'nion. Less than a year at the same rate. Single copy. 20 cents.

LETTERS
and inquiries are respectfully solicited from our readers.
The Exitor desires to receive current news matter and
articles on all matters of general interest pertaining to
sales.

OFFICIAL ORGAN
This paper is the official organ of the National Scale
Men's Association and the National Conference on the
Weights and Measures of the United States.

PURPOSE It is the purpose of the Editor to be fair in all matters pertaining to the scale industry. Every one who wishes to express an unprejudiced opinion in these columns is welcome to do so. We hope to promote honesty and square dealing in all phases of the scale business, from manufacturing to testing and operation.

ADVERTISING Rates furnished upon application. The Scale Journal as a medium reaching the buyers of scales, testing apparatus, tools, warehouse equipment, etc., furnishes auver. tisers maximum service at a miniinum cost. Entered as second-class matter October 23, 1914, at the postoffice at Chicago, Illinois, under the act of March 3, 1879.

Vol. 5. No. 2.

CHICAGO, NOVEMBER 10, 1918.

$2.00 Per Year.

ORLD events of paramount significance are transpiring with

such rapidity that we who live now, live a generation in a day. VV Important history is being made every hour.

The readers of this JOURNAL are individual units in the sum total of human events. One cannot pierce the veil of the future. Our vision is limited to now, even though we would see beyond the heights. It is not for us to imagine the burden of reconstruction is upon our shoulders; but it is for us as citizens of a great country to accept individually the burdens which peace thrusts upon us. Civilization has been laid low by the ambition of the Prussian pirates, but their hour has come. In the wake of war unprecedented political and economical problems will follow. We may be but an insignificant factor in the solution of those problems, but there is one thing which the inhabitants of the whole world are called upon to do now as they have never done before, and that is to make each individual effort count for the most—that is the effort which we expend in our vocations. That man who makes minutes produce results where minutes have been wasted before will render to society in peace times, service which is comparable with that of the soldier on the battlefield. We are called upon to achieve greater results through our individual efforts than ever before. Civilization withstands war because men unite to fight for a principle which they understand. When the fighting is over then the test of civilization really begins. Let us carry on for better results in our industry.

Prompt and Fair Settlement of

Just Claims for Grain Losses

Rosenbaum Reviem

is the goal that carriers and shippers alike are seeking. Authoritative weights, i. e., weights that are correct beyond a reasonable doubt would save both parties the time and money wasted in litigation and disputes. They would also conserve needed grain by revealing immediately sources of loss.

The New Richardson

5c Per Copy

$ 2.00 Per Year Published by the J. Rosenbaum Grain Cou

Edited by J.RALPH PICKELL

AN AD-LESS PAPER WITH A PULSATING PUNCH! WE WANT YOUR GRAIN BUSINESS! YOU NEED OUR GOOD SERVICE! A SPECIAL DEPARTMENT FOR EVERY PHASE OF GRAIN MERCHANDISING, MANAGED BY

HIGHLY TRAINED AND EXPERIENCED MEN MAKE FURTHER INQUIRIES

HAVE YOU READ MR. PICKELL'S LATEST?

Self-Compensating Type Registering

Automatic Grain Scale

fulfills this ideal.

417 POSTAL TELEGRAPH BUILDING

CHICAGO OMAHA - KANSAS CITY- OKLAHOMA CITY FORT WORTH - GALVESTON - NEW YORK

AND OTHER IMPORTANT POINTS

Here are actual results obtained on a test of a 10-bushel shipping scale at plant of Crabb, Reynolds & Taylor, West Point, Ind., Sept. 20th, 1918.

Scale Operated Same Scale Operated at 2250 bü. hourly

at 750 bu. hourly 0. K.

-3 Oz O. K.

0. K.
O. K.

O. K.
O. K.

O. K.
O. K.

-5 Oz.
O. K.

O. K. -3 Oz.

0. K. O. K.

-5 Oz. -3 Oz.

-4 Oz. -3 Oz.

0. K. -4 Oz. Greatest error on single draft of 560 lbs-5 oz. light. Average error 11 oz. light per weighing: Total error 30 oz. light in 11760 lbs. of corn or .016 of 1%.

The New Richardson weighs, counts and records without human assistance, irrespective of variations in gravity of grain being weighed or rates of flow.

It is an impartial arbiter between shippers and carriers and its acceptance will save both-timemoney-trouble.

Richardson Scale Company

PASSAIC, N. J.

Scale Journal

Vol. 5. No. 2.

CHICAGO, NOVEMBER 10, 1918.

$2.00 Per Year

PART I.

The vibrations of a beam in a platform scale have often been compared with the movement of a pendulum in a elock Both have evidently a motion which is not perpetual, the clock will me to a stop when the spring or the weight ceases to act, also the scale beam will come to rest when an over weight appears or friction between moving parts exceeds the expended force, by which the vibrations were started. In general a pendulum is a body swinging or oscillang about a fixed point. The simple ideal or mathematical pendulum is a weightless line or wire, pivoted at the upper end and carrying a bob at the lower end. When disturbed from its vertical position, oscillations or beats 'ake effect, whose duration or period depends upon the length of string or wire by which the bob is suspended and the attraction of the earth. A not moving pendulum is therefore held in vertical position by the power of the earth. Impulse of motion and friction exhausted elf, until the attraction of the earth grows larger and commands the state of repose. During the performance, from pressure of bob, wire and friction upon bearing heat and wear are generated, compensating in this manner the exer

Oscillations In Scales

By EUGENE MOTCHMAN
Mechanical Engineer

Standard Scale & Supply Co., Pittsburgh, Pa.

The power of attraction causes all free and unsupported bodies to tail to the earth at varying speed, the farther the object from the surface the smaller the attraction, approaching the earth the speed increases. A falling body under the action of gravity alone, is a case of uniformly accelerated motion, amounts to 16.16 feet per second and acquires a speed of 32.2 feet per second at the end of first second. The force of gravity varies slightly at different latitudes, at 45 degrees the velocity for the first second of descent is 16.083 feet. For practical purposes the following table shows the velocity of time (t), distance fallen through in feet (h), velocity acquired at end of time in feet (v) and space fallen through in last second of fall in feet (s).

t

h

S

1

16

32

16

2

64

64

48

3

145

96

80

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t= 6.28 51 3,2 Seconds.

When "g" the constant acceleration
32.2 ft.
t=v/g.

v = g/t.
h = vt/z.

A scale beam under impulse of over weight also falls some small distance which rarely exceeds 2 per cent of long arm, and suffers acceleration which must be considered with the constant "g" equal 32.2, appearing in all time-formulae on oscillations under the action of gravity.

For the simple pendulum the time of oscillation is depending upon the length of string and this accelaration "g", the weight of the bob is immaterial.

Then (1) t = pi (L/g)'.

When "t" time in seconds of one passage from right to left or reverse, pi the constant of a circle radius one (1) 3.14 and L the length in feet, index 1⁄2 indicates the square root to be extracted from the fraction (L/g) and also in following formulae.

A pendulum 9 feet long will beat: t = 3.14 (9/32.2) 3.14 X .53 seconds.

- 1.7

The length of a simple pendulum from its point of suspension to the center of gravity of the bob is directly proportional to the square of the time for one beat:

Thus, 9:2.89 - 3.12:1.

Let 9 the length of pendulum in feet 2.89 the square of 1.7 seconds 3.12 ft. the length of second pendulum 1 the time of beat in seconds.

To obtain a normal pendulum which will beat exact seconds, it must be:

(2) L- *pi*

numerized: 3.26 ft. 32.2/9.86

or 39 12 inches.

By experiments it was discovered that the length of a second pendulum varies on different parts of the earth, it is greatest in the extreme North and South, smallest at the equator, at London (England), it is 39.1393 inches. This indicates and proves the attraction of the earth, its density and form are not uni

form, hence the value "g" also fluctuates, namely near the poles 32.255 foot pound seconds, in London 32.191, at the equator 32.091. Our assumption of 32.2 is therefore an average suitable the purpose.

The

A simple, ideal or mathematical pendulum as described exists in theory only, because a uniform bob and weightlessflexible rod cannot be procured. weight of the rod retains an influence upon the time of vibration and requires to be treated as a compound pendulum.

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(6) h=Bg/A+C= 4.76 inches from c. This result will coincide the practical The experiment upon triangular file. center of gravity of beam and poise alone is determined by experiment upon triangular file or by the following method: s like the following:

Square root of difference B (f + d)2 minus C n' divided by A plus B, see Fig. 1, where "n" the distance from center of gravity "h" to pivot 6, expressed by formula:

(7) s = (B(f + d) - Cn2) 1⁄2 A+B numerized s = (334.11-52.95) 2 ÷ 8.78 = 1.91 inch. After these centers of gravity are established all data to compute the moment of inertia are on hand.

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This Scale Beam, Fig. 1, with its many attachments, balance ball, poise, counterpoise, load and loose weights increases the problem, but obeys the law of the compound pendulum, which has a vibration in seconds:

(3) t = 2 pi (K2/dg)*

When K the radius of gyration, "d" the distance of center of gravity from center of rotation, other smybols as before.

From the square of the radius of gyration K and d, a dignity is created by dividing, K' with the distance "d" only. The quotient is a mathematical quantity of great usefulness and importance. This dignity is the radius of oscillation "r", its function and relation is the proportion:

(4) r: K = K:d

leading to the formation of the moment of inertia which is:

(5) I= MK'

When M the aggregate weight of beam and loads, K' to be determined by trial and method.

Experiment.

For the purpose of investigation, a platform counter scale, catalog No. 1212, Fig. 2, is selected, its capacity is 300 lb. weights 1 to 50 lb., beam graduated 10 lb. by 1⁄2 lbs. To review the time of oscillation obtained from this beam and scale above formulae will be used, some properties are arrived at by measuring, others by weighing, experimental trial and calculation.

Preparation.

Remove beam from scale, weigh it
with balance ball and poise but without
loops exact to 4 ounce, this quantity is
called A and weighs 2.44 lb. Next weigh
the counterpoise and its loop at the tip
of beam as it balanced scale complete,
name it C .89 lb. Measure within 1/100"
the long arm of beam "1" 121⁄2 inches
To
also the short arm "f" 21⁄2 inches.
find the weight B return the beam with
loops and counterpoise to its place in
scale, from the butt loop at end of beam
from pivot "a" pass a chord through
pillar and hang ballast to it until the
beam oscillates with counterpoise at the
other end, but without levers and plat-
form, the poise, of course, points to zero.
Ascertain now the weight of the ballast,
chord and butt loop it will be B 6.34 lb.
To find the center of gravity "h" of this
combination, beam A and Counterpoise
C without B at opposite end experimen-
tally, secure a triangular file and balance
the combination upon it as seen in Fig.
1, then measure from the corner of file
horizontally to the edge of pivot "c" and
this distance "d". Likewise

name

f
•2.5 1.91°

B-36.34 Lb.

Method.

1. Moment of inertia of a body.

This quantity is difficult to prepare
from dimensions of irregular shaped
bodies, and more so from a combination
as demanded in this case. A maximum
moment of inertia which meets all fol-
deductions in
lowing conditions and
sense of accepted practice is:
(8) I= As' + Bf2 + Cl2 + (A + B + C) d'

Applied 8.88 +39.62 + 139.06+ 219.02
I= 406.58 lb. inches squared.

As seen the moment of inertia contains the effective weights A, B and C at proper distances from rotation center plus the entire mass about center of gravity "h" by distance d'.

2. Radius of Gyration.

The center of gyration "i" is that point of a rotating body at which the entire mass, beam and weights possesses the

1=12.5"

T= 12.67.

8.9.72
·K= 1LI

e:295

FIG. 3.

A=2.44Lb

I=5627, K2 123.21; d2 94.47, dg = 312.98.
M= A+B+C -45.67 1b, e2 8.1 eg= 94.99
ag

+= 2x VK2 = 2× √ √ = 2x √RE O

tz 6.28 x.62 = 3.8 Seconds.

balance the beam only (2.44 lb.), and
locate the center of gravity "s" to 1.91"
from pivot c, which is also known as the
center of rotation. The weights A, B
and C produce 3 distinctly different
centers of gravity s, h and c whose posi-
tion can be definitely determined in any

case.

By calculation from known data the center of gravity "h" can be found by the equation of moments about pivot "c" from known items.

C 6.89 Lb

PS45%

same energy as at point of rotation, it cannot be at the centers of gravity c, s and h nor at the center of oscillation, but lies on a straight line between center of gravity and center of oscillation. This radius of gyration K is the distance from center of rotation to center of gyration. Then is the square of this distance K an average of all distances from "c" to each elementary particle and weight of the combination (beam,

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