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NEW RULE FOR MEASURING ROUND TIMBER.

Sir,—The following paper is the production of a person in this town, whose acquirements in mathematics, mechanics, and general knowledge, are entirely the result of his own abilities and application, without having derived advantages of any description from education--in fact, he was brought up as a bricklayer, and even follows that calling at the present moment. He was recommended by me to take in your admirable Work, with which, on all occasions, he expresses himself extremely pleased. Should you deem it worthy of appearing in your pages, he will feel much flattered ; and, on future occasions, you may find him a valuable contributor to your work, and a striking exemplification of the power of natural talent. I am, Sir, your very obedient servant,

E. S. STRATTON Reader. St. Bartholomew's, near Sandwich, Kent.

SIR,I take the liberty of request. tents are required; and the second is ing the favour of your inserting the the mode or rule of calculation. In: following brief remarks, experiments, regard to the former, the method of and subsequent calculations, relative girting may be comprised in a geneto Round Timber Measure. Your Cor- ral rule, to be observed with some rerespondent T. H.'s views on this sub strictions, hereafter to be noticed. ject agree with mine; but as T. H. has The method or manner of girthing I not illustrated the observations he has would recommend is, in the first place, offered on this head altogether satis- to divide the length of the tree into factorily, in my opinion, I will, with several equidistant parts or portions, due submission to him and the rest say five or six; then, with a small cord of your mathematical Correspond- or line, as usually made use of, girt ents, submit the following explicatory the tree where the points of division remarks:- :

may happen to fall between the two My principal intention is, to demon- ends, taking in at the same time the strate an approximated method of mea girt of the ends, or nearly so, as may suring round timber; at least, such as be thought proper (vide remarks submay, in some degree, approach nearer joined). This being done, the mode to the truth than the rules hitherto of arrangement and rule of calcugenerally made use of by calculators. lation, in the latter particular, is as But, before I proceed to give the expe follows :riments and calculations, I beg per

Let G be the sum of all the girts, mission to lay down a general hypo

and n the number so taken : then will thesis, to be regarded as a standard in an investigation of a proposition which be = m, the mean or common girt; has for its object a new theory, which shall be every way subservient to the

and hence the rule of computation is mechanical practitioner. Now, as irregular pieces of timber

ml x 2 – mx.025 = A, the approxi(trees) consist of various shapes, such as obtuse ellipses, distorted circles,

mated area of the compensating mean and, in many instances, a sort of tri

girt, which area is to be multiplied by angular or trapezi-angular formed sec

L, the given length, as LxA = 0, tions (were the same sawn asunder in the cubic quantity required. - (See several places), to find the true mean

Remarks.) area of the many sections or quantities contained within the circumscrib

Illustration of these Rules, by actual ing compass of the respective virts,. , Experiments, to ascertain the Cubic when taken by actual measurement, Quantity of Round T'imber. is what I apprehend to be the chief Having provided three models of difficulty. The first particular to be wood, in the shape of round, timber, observed consists in the method of retaining the several inequalities incigirting the tree, or piece, whose con- dent thereto, and having likewise pro

n

101

28.0

NEW RULE FOR MEASURING ROUND TIMBER. cured a tube sufficiently large to adinit

To No. 2. each piece separately, I filled the tube, having one end stopped, with water,

Girts. and then reserved the quantity in a cy

No. 1 = 38.76 Length = 72.5. lindrical vessel, to be properly guaged.

No. 2 = 36.5

ditto The tube being now empty, I put in

No. 3 = 37.6

ditto one of the models, marked No. 1, and

No. 4 = 36.37

ditto then poured in the water I had re

No. 5 = 34,42 ditto served till the tube again was filled;

No. 6 = 34.00 ditto the remaining water in the vessel being

No.7 = 35.00 ditto equal to the cubic quantity of the modelized piece of wood. Then, with a

7 = n) 252.65 sum of girts G. guage or scale of equal parts, 1 guaged and calculated the respective quantity

36.092857 =m, mean girt.. found in No. 1. I proceeded in this manner with the other two models, calculating the respective quantities in

To No. 3. decimal proportion according to the divided scale of equal parts, setting

Girts. down the result corresponding to each

No. 1 = 28.5 Length = 59.8. number or model. The next thing I No. 2 = 28.3 ditto bad to attend to was to divide the No. 3 = 28.6 ditto models into equal portions, in order to

No. 4 =

ditto girt each as per rule (obtained by trial);

No. 5 = 28.7

ditto then, with a very fine thread, Í began No. 6 =

ditto with No. 1, at one end, to girt the No. 7 = 27.5

ditto model, measuring the length of the girt by applying it to the same scale 7 = n ) 196.6 sum of girts «G. of equal parts as I made use of to guage the vessel. The length of each

28.0857=m, mean girt. girt I set down, and collected their sum as per rule, which are as follows:

The Division of Quantities for CalcuResults and Calculations obtained by

lation,
Experiments.

Quarter mean girt. 1-5th of m. girt.
To No. 1.
To No. 1 = 9.475

= 7.58
Girts. . .

No. 2 = 9.02321425 = 7.21857 1 No. 1 = 38.6 Length = 66.22. No. 3 = 7.021425 = 5.61714 No. 2 = 38.5

ditto No. 3 = 37.7

ditto The reserved quantities, as calculated No. 4 = 38.0 .. ditto

from experiments of immersion in the No.5 = 37.5

ditto No. 6

tube-dimensions of vessel omitted. = 37.7

ditto No. 7 = 37.3. ditto

Cubic quanti

ties obtained. • 7 = n ) 265.3 sum of girts=G. To No.1, (accurate guaging)=7592.980164

No.2 ditto =7442.026284 37.9=m, or mean girt.

No.3 ditto =3773.847

27.0

Quantities per Rule and Girts, as proposed by me.
To No. 1 ..... 7.582 x 2-37.9 x .0252 25469116
Multiplied by ...... 66.22
To No. 2 : 7.2185712 x 2–36.092857 x.0252

"} = 7438.5568
Multiplied by i... 72.5
To No.3 .5.61714? x 2-28.0857 x .0252

} = 3731.6708
Multiplied by . ...i . 59.8
Quantities calculated by the common Rule, hitherto generally practised.

To No. 1 i... 9.4752 x 66.22 = 5945)
To No. 2iii 9.023222 x 72.5 = 5911 Decimals omitted.
To No. 3 ... 7,021152 x 59,8 = 2948)

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J02
NEW RULE FOR MEASURING ROUND TIMBER.

Girts.
REMARKS.

No. 1 = 78 inches.
These results show that the custo-

No. 2 = 69

No. 3 = 60 mary rule makes the quantity a great

No, 4 = 66 deal too little, while the rule I have

No.5 = 53 adopted comes very near the truth, as

No. 6 = 58 may be seen by comparing the cylin

No, 7 = 40 drical quantities to those ascertained

No. 8 = 43 by calculation.

+ 8) 467 sum. The following is an example, by

Mean girt..58.375. duodecimals, applicable to the new rule :

Then, per rule, S = 11.675; Take a piece of round timber, whose which, being duodecimally expressed, length is 42 feet 6 inches, and girts as is = 0 ft. 11 in. 8p, I s. 3ti, &c. Say, follows :

then, per rule

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former quantity, leaves a difference of 18 çubic feet, which is of soune innportance to those who carry timber by weight. ...

If the piece had been calculated by the customary rule, the quantity would be several feet less, which, to avoid figures, I abbreviate thus :

jste thue 58.375

6 = 14.59. Say, 14.6 in. = 1 ft. 2 in. 7 p.; then, 1, 2, 7* = 1 ft. 5 in. 8 p. 8-s. I t., which, being multiplied by the given length, gives quantity = 62, 9, 2, 7, 6, &c., which, being deduced from the

* The correcting factor is 1 in 40, which, for 58, we may take 1}; which, when the duodecimals are squared, every unit, or 1, will be parts, making li l-6, as above,

HARDENING STEEL-WHEEL-CARRIAGES.

103 If one end of the tree be suddenly sharp-do sharp my knife!" is the order much larger than the rest, girt the of the day. I try to sharp, but no edge mean or half the distance between

is to be obtained. I give one, two, three, where such suddenness of bulk com

and four shillings a-piece for knives,

and there may be one out of half a dozen mences. If the tree is regular through

that may be worth sixpence, and will out, from end to end, and the girt

cut a little ; but that is all. Pray put

another spur to this edge-tool business, small, the rule, x 2 xL, will not and you will confer a favour, I am sure,

on hundreds, as well as myself. greatly, if at all, exceed the truth.

I am, Şir, &c. But as no trees are truly circular, the

A CONSTANT READER, correcting factor, m. x .025, should be used. Also, if a tree be of a triangular

6, East-place, Lambeth, May 16. form, from end to end, the correcting factor should be mx.25 ; but, in all other cases, the preceding rule appears PROPOSED IMPROVEMENT ON to me admissible, unless that any dis

WHEEL-CARRIAGES. covery in measuring leads the calculator to apprehend that the mean girt is too little, and, consequently, the mean area too little, which would be difficult to determine, as a variety of circumferences may occur in which there may be but little variation in the area of any respective section.

Thus far I have attempted to establish a new rule for computing the cubic quantity contained in irregular pieces of round, unhewn timber, The method of girting gives the equalizing area, and the rule of computation, in a few figures, the cubic quantity.

I now leave the subject to the correcting remarks which apy of your mathematical Correspondents may think proper to make, and shall reserve other observations on this head for a future paper, trusting that what is here advanced may be found not uudeserv. ing a place in your esteemed work.

I am, 'Sir,
Your most obedient servant,

HF-
Fisher's-street, Sandwich,

IMPROVED PROCESS OF HARDENING SIR, I shall be glad to know from turidi , se STEEL.

some of the Correspondents of your Str.-It gives me some pleasure to see, valuable Magazine, qualified to give in Number 90, page 90, of your valuable an opinion on the subject, whether any little work, the Mechanics' Magazine, ease would be afforded to a horse by an article copied from Nicholson's Ope-. the adoption of a plan, of which I rative Mechanic, just published on this head. By this I trust you will stimulate

have endeavoured to convey an idea

mave some of our manufacturers to set about

by means of the above draft. improvement in good earnest before it is

Description, too late. For my own part, I have for some time past given up all hopes of ever A and C are the shafts of a carriage. having a good knife again, unless by BD, a bar connecting them. chance. I wear out a great many pencils, and my wife who has about thirty young

EF, a bar connected with the carriage. ladies to teach writing) a great many Two springs are fastened to EF, and pens, froin the want of one." Sharp work against BD,

104

CANAL ECONOMY-SHARPING RAZORS, ETC. G and N are two stops, fastened to Halifax, Naturalist.' He said, “ the EF, to prevent the springs being over: strops sold in the shops were covered strained, and against which BD would

with black lead :" so it rested—but rest when the springs were strained to a certain point.

mine set a finer edge, and I use it The shafts A and C would pass through

och still. The discovery was simply this : two holes made to receive them in EF, A Bible, in rough calf, lay (except and would, together with BD, be move when used) on a pewter dish turned able, so as to operate on the springs. bottom up; the book being shoved

I much fear I may not have ren- ! thereon got a coating of metal ; I dered myself intelligible, as I am not was in the habit of strapping my at home at mechanical terms, and razor on it, and found it shave better. that my ignorance of mechanics may than when done on anything else. have induced me 'uselessly to trouble There was not then those facilities you ; but, from the consideration I for such little (and, of course, useful) have been enabled to give this plan, things being made public, as are now it occurs to me, that by its adoption furnished by the Mechanics' Magaa horse would be much eased at mine and other works of a similar starting, and on meeting with any description. obstruction in the road.

I am, Sir, ,
I am, Sir,

Your obedient servant,
Your obedient servant,

A CLUMSY MECHANIC. Bath.

R. E. Halifax, 29th April, 1825.

CANAL ECONOMY. Mr. David Townsend. of Penn. THE “ STEAM WASHING-Box.” sylvania, has invented a method of INFORMATION WANTED. saving water as the boats pass through Sır, Will you allow me to ask the locks of canals, by which not a Mr. Haspy Smolet, through the megill, it is said, will be lost. By the dium of your pages, whether the deapplication of a machine, on all scription of the method of Washing summit levels, no more surplus water by Steam, given by him in vol. iy. will be required than will be lost by p. 21, is the result of actual trial filtration and evaporation : there is successfully made, or otherwise ? I no filling of locks by side or sluice ask this question, in the hope that gates, and the strength of a single such of your readers as may be dismay, with a simple mechanical power, posed to make the trial, will defer will do all the work, and pass a boat doing so until they receive his anin half the time required on the pre- swer; for, some years ago, in consesent plan.

quence of a similar account of washing by steam, in Rees's Cyclopædia,

under the head Laundry, I made SHARPING RAZORS.

the attempt, very much in the way Sir, I congratulate mechanics Mr. S. describes; and although I on the appearance of your work : consider I gave it a full trial, I enlike the morning sun, your pages tirely failed. I tried the steam at will disperse the mists and clouds 2120 and higher temperature, and which häng on the mechanic's hori, both soaked and soaped the linen Zona Has he any doubt of his little previously, but could not produce the discovery or invention being new, he effect of cleaning it, though the linen can now make inquiry till he be satis- was exposed to the steam .tenor fied, and then the way is open even to twelve hours, and consequently I him, which was not so when I was concluded that some additional apyoung. Your second volume con- plication of pressure or friction was tains a method (from the Glasgow necessary. Magazine) of setting a fine edge on

I am, Sir,;. a razor: I have used the same for Your obedient servant, : * more than thirty years, and then

- Ji S. M. mentioned it to James Bolton, of 7th May, 1825, s...

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