continuous roll, but while the Times machine takes up
a great deal of room, the Bullock is very compact.
The former divides the sheets after the impression, as
it is only by the hold the cylinders have on the paper
that it is drawn through the machine. The latter cuts
its paper just as the grippers seize the sheet to take it
ander the first impression cylinder. Both machines
damp their own paper.
A speed of 11,000 an hour is
computed for the Walter machine; but in the descrip-
tion of the Bullock, p. 609, vel. x., no speed is men-
tioned. Now in any machine there are three absolute
requisites:-The cylinders must be so arranged that
the plates can be readily laid on, i.e., "made ready;"
there must be no danger of any of the parts continually
"breaking down;" and the whole must be so arranged
that "register" can be easily made and maintained.
With these hints I leave the matter in the hands of "our"
inventors, assuring them there is a fortune for the
man who succeeds. A simple machine is more likely
to achieve the desired result than a complicated one;
but nevertheless, cæteris paribus, a machine that saves
five minutes in each hour has very great attractions
for the managers of morning newspapers. Readers
should carefully examine the drawings I have men-
tioned above; and if anyone sees his way to make an
improvement, I shall be always happy to help him.

SAUL RYMEA.

SQUARING THE CIRCLE.-CONIC SECTIONS. [126] SIR,-My approximate rectification of the circle must yield the palm to the one given by "A Member of the English Mechanic Scientific Society." His plan and Mr. Penrose's approximate trisection of an angle must be regarded by all mathematicians as very valuable contributions to the ENGLISH MECHANIC.

The remarks made by "a Ursa Minoris " (4351) accurately describe the distinction between the ellipse, parabola, and hyperbola. It is well to notice that the name hyperbola is not limited to sections made parallel to the axis of the cone, as is sometimes stated. RICHD. A. PROCTOR.

the

CONSTELLATION NAMES.

[127] SIR,-I think the criticism on this subject in kind review of my atlas is just; and very much fear my new constellation names will have even

very

tually to be abandoned. Felis was a name given by

Bode to a constellation he invented. I thought of Ursula for Ursa Minor; but as Ursula is a lady's name I trembled at the thought that I should seem to suggest that all Ursulas are little bears. It would be worth while to make an effort to retain the new and much shorter names, using both for a time, as in my introduction. They are few, and I think they are manifest improvements. Some of them were suggested to me by Sir John Herschel.

RICHD. A. PROCTOR,

MR. PROCTOR AND PROFESSOR PRITCHARD. [128] SIR, Mr. Brandon is very personal while objecting to personality in me. And further, whereas I wrote only what I knew, he rashly writes without knowledge. It sounds very fair to say that if Professor Pritchard's review on my book is unjust, "the merits of the book will answer the criticism." A review, however, is not written for those who have read, but for those who have not read a book. How the merits of a book can convince those who may be deterred from reading it by an unjust criticism, I leave Mr. Brandon to show. But as a matter of fact every one acquainted with publishing knows that an unfair review, if unanswered, invariably does mischief. As in this case the whole loss would have fallen on Messrs. Longmans & Co., I had a duty to fulfil in the matter.

I have said that Mr. Brandon writes without knowledge. He throws out the suspicion that I have tried to steal a march upon the Savilian Professor by sending a letter to the ENGLISH MECHANIC, having reference to a review which appeared elsewhere. This personal insult finely illustrates Mr. Brandon's objection to personality. Let him now learn that, first, I addressed a letter to the same effect to the paper in which the unfair review appeared; secondly, I wrote to Professor Pritchard telling him what I felt it my duty to do; thirdly, I offered to send him copies of all such comments as I might make, in order that if he thought fit he might reply to them; fourthly, he has sent me privately a reply to the three chief points of my counter charge. I do not feel at liberty to mention the terms of this reply, and only remark respecting it that it does not meet my statements.

ROMAN NUMERALS.

BRINSMEAD'S HISTORY OF THE PIANOFORTE,

AND A "LEETLE " MORE.-LETTER I. [182] SIR,-Having in No. 227, of the ENGLISH MECHANIC analyzed to the best of my very small ability Messrs. Brinsmead's so-called improvements in pianoforte actions, I now, as seemeth in duty bound, proceed to analyze a new book of the pianoforte, which is the production of a member of that firm, to the general goodness of whose productions (other than literary) I can with much pleasure bear testimony. In justification of my doing this I will, with your permission, Mr. Editor, relate a short passage in my own personal history which, for the important moral truth and lesson of charity it contains, may, perhaps, not be unacceptable to my fellow-readers.

[129] SIR," J. R. W.," p. 311 (No. 4048), asks. "How did the Romans perform arithmetical operations with their Z's, Y's, and X's ?" The Romans never employed the letters Y Z in their notation; but I will endeavour to explain their use of the characters of the alphabet for the purposes of counting and numbering. Some very ingenious suggestions have been made as to the origin of the use of letters to represent numbers, and one of these certainly has some pretensions to be the true explanation. It will be allowed, I suppose, that the most likely way anyone ignorant of figures Thus, would count would be by the use of his fingers. then, we have from 1 to 10 enumerated on the fingers, and written with ten strokes; but it is quite feasible to suppose that when ten strokes had been written down the numerator would make some mark to show that his Many years ago, a friend of mine, who did the duty hand was full. We will suppose that he drew a line in to which it pleased Providence to call him, by selling a diagonal direction through these ten strokes, and it tea and coffee in the city for six days per week, but who, is easy to believe that in endeavouring to shorten this instead of resting on the seventh, or rather the first he would make a character somewhat resembling the day, used to preach what he believed to be the "word letter X. Then to make 100, as one mark across the in season" every Sunday morning in his own chapel, unit stood for 10, he would very likely put two ligatures he being a "master of words i.c., eloquence, which to the unit for 100, forming a character resembling C, I am not, I once strongly urged him as a matter of which in writing would soon be turned into C. As remoral duty to preach against certain and sundry vices gards the 1,000, the unit mark would require three of great cities-I may sorrowfully add of rural districts ligatures, which might be made somewhat like M, and also which I had been writing in condemnation of as in course of time would probably assume the form of strongly as my very small command of language (com, which actually appears in print and in inscriptions bined with an amount of earnestness which those who as CI. Having arrived at these it is easy to see that only know me in the disguise of chaff would not give V is but the half of X, L the half of C, and D the half me credit for) enabled me to do. After some time of CI. We then have the fact that in Roman nume-worthily spent in thought, my old friend said to me, “S. rals wherever the lesser symbol precedes the greater, cannot make duty for B. any more than B. can make under 100 it is subtracted, but afterwards it is added. duty for S. Each servant of the Most High must find Thus the unit mark I, the X, and the V are used as far his own duty, and do it, with Heaven's help, to the best as 40 (XL, 10 from 50), after which the L is used up to of his ability." After such a moral lesson as this, which is reversed and the unit mark prefixed (19); hence into my mind, and assisted me in after life to judge XC (10 from 100), C is used as far as 400, after which it I trust by the force of its inherent truth sunk deeply D 500), and so on up to 1,000, when the mark above- charitably of what often seemed to me the misdirected noticed is used (CI), or M, or the unit mark with a efforts of many whose gifts far exceeded mine, I felt line over the top (I); 5,000 is written I or V, the rethat it was not my mission to call my fellow-labourers versed thus acting as our 0, and multiplying by 10; in the Lord's vineyard of knowledge to account, but to so 50,000 was written 1000, and by putting the same bear my testimony to what seemeth good, and point out number of C's before the unit as reversed ones occurred apparent evil. My friend, whose loss I deplore, further after it, the number was doubled, so CCCI = 100,000, said, no doubt you think I ought to bear testimony and 19951 (500,000) is thus turned into a million against these things, and could i but see that my doing CCCC13559. One peculiarity of Roman numerals is so would induce more good than evil, it would indeed become my duty to do so; but you have fallen into the

worth mentioning, viz., that the various letters used are

alternately quintuples and doubles of the preceding

one e.g. I x 5 = V; V x 2 = X; Xx5=L; Lx 2 =
arithmeticians (if there ever were any) had arbitrary
C; C x 5 = D; D x 2 = M. Whether the Roman
signs to denote the different values is not known,cer-
tainly none have been discovered. My own opinion is
that they knew nothing of the science of arithmetic,
and what calculations they made had to be worked out
with the cumbrous numerals I have endeavoured to ex-
plain.

[130]

FRICTION WHEELS.

SAUL RYMEA.

SIR.-I see from the fourth page of the advertising sheet of our present number (277) that Messrs. Forder & Co. have, either consciously or unconsciously, adopted an old idea of mine which I suggested as far back as January 15, 1869, namely, the application of friction wheels to velocipedes; and, strange to say, about the same time I made a model exactly similar to Fig. 2 in their advertisement, which is now in the possession of Messrs. Wilson and Longbottom, of Barnsley, who joined with me in taking out a provisional patent for the application of friction wheels to all kinds of velocipedes. We did not proceed with the patent because we decided, after various trials with ordinary bicycles side by side with one fitted up with friction wheels, that the advantage gained was hardly worth mentioning.

on

On smooth boards the difference was perceptible, but the friction wheels by no means compensated for the roughness of the ordinary road. I feel certain that improvements are not so much needed in the velocipede itself as on the road on which it runs. The extreme ease with which a well-made velocipede moves smooth boards or flags, and the greatly increased exertion which is required when riding on the highroad, show that the impediment to progress is not to be looked for in the friction of the bearings, but in the roughness of the road. Wheels with india-rubber tyres seem to me to be a step in the right direction, as a velocipede fitted up with them may be said to lay down its own road as it goes along.

W.

HAND-PLANING MACHINE. For the rest, Professor Pritchard's quotations from my book, and the book itself, are before the public. If [131] SIR, A good drawing of a hand-planing anyone is anxious to take up the cudgels in defence of machine (p. 429) is given in your current number. But Professor Pritchard, let him show that the quotations the price quoted is very heavy, and might discourage are fairly made, that I have really said (in effect-not your readers from attempting to obtain this useful in words pieced together unfairly) what Professor Pritchard has asserted. To such evidence I shall gladly listen; but I can allow no question of my right (with your permission) to correct in your columns what I take to be erroneous and unfair criticisms. I have made it a duty to correct errors respecting scientific matters, errors affecting the repute of others, all errors, in fact, which touch on the subjects I take interest in; I also carefully admit errors I make myself; surely I may be allowed to correct errors by which, if I permitted them to remain uncorrected, the publishers of my work would suffer.

Lastly, I object as much as Mr. Brandon can to personality, but personality in attack is one thing, personality in self defence is a very different one.

RICHARD A. PROCTOR, B.A.

tool. I may, therefore, state that I have made one for
myself at a price of about £10. It admits work 18in.
by 14in. by 6in. The castings were made and planed
for me by Pearce, of Union-street, Borough. They
can also be had ready planed of Thomas Taylor, 7,
Chester-street, Hulme, Manchester, for £7, taking in
work 24in. by 134in. by 11in. Mine works with a rack
and pinion of 7in. pitch, and a double handle, which
gives a longer stroke than the lever. One of the small
American parallel vices fixed to the table serves to
hold small work, and costs only £1, instead of £7 10s.
A few carriage bolts, costing about a penny each, and
some iron dogs complete the machine. The work is
set true by a good T-square, and can be removed and
replaced under the tool with very little more trouble
than in an ordinary vice.
W. H. STONE.

very common error of supposing one man can make duty for another, which error is the root of all persecumen's duties for them. One of those found, or perhaps, tion." Since that time, I have endeavoured to find my own duty, instead of presumptuously finding other self-imposed duties, is to examine, judge of, and comwhat matter is published concerning their history. In ment on so-called improvements in pianofortes, and the execution of that duty I proceed to treat of Edgar Brinsmead's "History of the Piano," for which I felt in duty bound to pay 3s., or rather 2s. 6d. N.B.Don't forget the customary allowance of 2d. in the shilling on all new works which competition saves us who are rather copious, if not liberal, buyers of new books.

In a former paper on the pianoforte and its congeners I have said that its true history-certainly the true history of its early manufacture in England-has yet to be

written. Brinsmead's book has not induced me to alter

that expression of opinion, but as the writer or com piler has collected into a small space a good many facts and sayings of the order of " things not generally known "about music and musical instruments, which will probably much interest the majority of readers, who desire rather a brief precis on those subjects than to wade through the ponderous tomes of Hawkins, Burney, and a whole host of by no means lively English and foreign writers, who, like the blacksmith, are not remarkable for the terseness of their style. I can honestly recommend my fellow readers to follow my example, and invest half-a-crown in its purchase, and when they have "gone and done likewise" I venture to prophesy they will not regret its cost. I also trust that some of them at least may be sufficiently interested in this subject to expend one shilling and sixpence more for an illustrated catalogue thereof, and visit the very remarkable collection of ancient instraments of music deposited in South Kensington Museam for our "heddification." They are extremely well worth seeing.

The greater part of the matter contained in the earlier chapters of the work is so good that Dr. Rimbault thought it worth printing A.D. 1860, and he, at least, ought to be able to select and compile suitable matter relating to the history of music and early musical instruments, especially those having strings, with or without manual keys; but as Rimbault's matter is to a large extent copied from Hawkins, Burney, and other older and more modern writers-almost verbatim-so in Brinsmead there is little that is new, and much which, if true, is at least unproved.

One assertion, in page 38, is certainly new to me. The author says that Plenius, the talented inventor, or improver of the lyrachord, employed a circular bowa la hurdy-gurdy-to vibrate its strings, which he says were moved to the wheel or bow. What kind of wheel or circular bow could be made to act on the strings of more than two notes in an instrument whose strings were all in the same horizontal plane he leaves, as he found it, a mystery. It is just possible to make one wheel sound the strings of two notes if the said wheel be placed between them, and each pair of strings moved to it, but this is not using one circular bow, but many; indeed, half as many, less one, as there are notes in the compass of the instrument-(say) 29 bows or wheels for 60 notes.

This assemblage of wheels, yet further extended to

more than double that number, was used by Schmidt, of Paris, 1806, for continuing the vibration of the strings of a pianoforte, the tone of which was said to resemble that of the cymbal. Why, it would puzzle Apollo and the muses nine to say, but this was only one of many attempts in the hurdy-gurdy line "with variations." I may enumerate-first, John Heyden's clavecin viole, A.D. 1600, succeeded by Marins, A.D. 1717, whose model of a mechanical fiddle, with keys like a harpsichord, is said yet to be preserved in Paris. There was also Holfield in 1754, and many others, not to mention ye harpsichordis wyth gut strynges"-i.e., lyrachord, which Evelyn records that he went to hear. This," he says, "was made vocal' by a zone of parchment,' and that it sounded like a consort' of viols." In fact, it was a viol, it being a bow instrument with fixed intervals-i.e., our chromatic scale. This is just the distinction between viols and fiddles, and its action was rather more practical than using half as many revolving wheels as there are notes in the instrument, for it is obvious that-especially in instruments like the harpsichord, which has metal stringsmoving the strings to the bow (instead of the preferable plan of moving the bow to the strings) would have the effect of unsettling the tuning of them. At a later time it was done (under circumstances in which it did not have that effect) in that powerful keyed bow instrument, the claviol of J. J. Hawkins, for in this the hook which pulled the string to the very ingeniously constructed horsehair rotating bow-it Was not strictly a wheel, but an assemblage of horsehair bows inside a wheel, for its strings were attached to very long heliacal tempered steel springs-which resolved almost exactly the same amount of tensile force of its waterproof gut strings, whether they were quite straight, or slightly deflected to make them touch the bow. Under these circumstances their pitch was not sensibly altered; besides they were tuned when deflected, so as to be in contact with the bow, which it is obvious the steel strings of a harpsichord, having plectra also, could not be without great inconvenience.

Plenius would have had little inducement to torment himself by making and keeping in order, duly resined,

half as many wheels as there were notes in his lyrachord, for the endless band had been used nearly a century before his time. This is shown by my quotation from "Evelyn's Diary." Plenius, who was a very clever fellow, would, we think, have been about the last man to repeat such a mistake. The lyrachord existed until 1772 at least, for one was sold that year by the elder Christie. I trust it is yet in existence, and may adorn South Kensington Museum. To it my fine celestina harpsichord-its celestina stops were added by Walker, its inventor-would be a worthy companion, and I fully intend it to go there when completely restored.

In Brinsmead the old story that Plenius attempted to make a copy of the hammer harpsichord, known as Fulke Greville's piano, makes its customary appear. ance, but, as usual, no date is given when he made this alleged unsuccessful attempt. To this is added that the only pianofortes manufactured in England were those made by him. If I could suppose this true, small indeed must I assume their number to be. Trying, with small success, to make a copy of an existing piano, and making pianos for sale is something rather dissimilar, and the two statements are hardly reconcileable. That Plenius both tried and succeeded in making a mere copy is very probable, for no one who has read his patents can much doubt he was quite capable of doing something rather more than this. In fact, that he was a person very likely to succeed in any thing he attempted. The man who copied the old German and English harpsichord with gut strings, and improved on it to the extent he claims having done in his patents (which contain abundant internal evidence that the man who drafted their specifications knew very well what he was writing about, even if, as was the practice of his time, they are remarkable for the absence of specific instructions)-who anticipated refined modern practice by clothing the mortices in his keys-who double pinned his long bridges (au improvement not universally adopted by square pianoforte makers until about 1820), and effected other improvements which modern pianoforte makers use daily, little knowing to whom they are indebted for their introduction, was not likely to fail, even in his first attempt, to perform so simple and merely mechanical an operation as the making a mere copy of a hammer harpsichord is. No inventive power is needed for this, but I should be glad to be referred to the authority on which the writer states that he afterwards not only made pianos for sale, which is quite possible, but that he was the only man in England who then did so. On the contrary, the great probability is that this copy, when made, was like the original, so weak in tone that a Plenius, accustomed to what were then considered tolerably powerfal harpsichords, would have regarded it as the elder Kirkman did the piano of that date generally," a very poor, weak affair indeed."

Besides being very weak in tone, this copy was probably also very imperfect in its mechanism. Some of the earliest pianos did not even have their hammers supported on centres or hinges, but merely had strikers

fixed in the key-in fact the old tangent of the clavichord with some clothing on the top of it. With this kind of action it was absolutely needful that the finger should be lifted instantly after the string was struck, or its vibrations would have been stopped or damped by the clothed tangent or strikers acting on it as a damper. I suspect this is at the bottom of what we read about performances by "a maestro accustomed to the touch," &c., indeed, he must have been exceedingly well accustomed to such a touch to produce much effect. It was not until long after this time that English

pianoforte makers-and in this respect they take the
lead of their Continental brethren-appreciated and
carried out the instruction of their father in the art,
Christofali, who expressly says "that this kind of
(hammer) harpsichord should have much thicker strings
than the common sort, for then the objection that its
tones are weak doth not so much apply." Since his
time we have greatly improved his instruction. Messrs.
Broadwood, and other first-rate makers, now use No. 17
or No. 18 wire on middle C; and I, being a dissatisfied
person, constantly engaged in trying to improve and
make well better than well, have gone far beyond this,
I having employed No. 26 wire with great advantage
for that note, by altering the length, the place at which
the hammer strikes it, and increasing the weight of the
latter. This is what our American cousins would term
a "pretty considerable" advance on No. 7 or 8, pro-
bably the largest wire the father of the art ever used
for that note; for I doubt not he soon experienced the
difficulty of making the frame strong enough, as then
constructed.

The author goes on to repeat the old story that
the piano did not "at once" supersede the harpsichord.
It would have been a very unusual, not to say unpre-
cedented, circumstance if it had. Not to mention the
very grave defects in tone and touch of all the early
pianofortes known to have existed in England, of whose
mechanism I have representations-for Christofali's,
which is far in advance of them all, does not seem to have
been known in this country until a few years ago I
may just remark that it is not very common for new
things, however good, to supersede old things "at once."
We old fogies know very well in our hearts (at least we
should be afraid to deny) that young ladies and gentle-
men are, like all other new (Qy, green) things, far
superior to ourselves, their progenitors. Of course the
improvement in each succeeding generation is quite
manifest, at least to the angels which are in Heaven,
who view the human race from a high standpoint, if not
to our own imperfect perceptions; but somehow, these
clever young people don't push us from our stools and
supersede us at once." We elders have a prescriptive
right to be allowed a reasonable time to "die ont."

just so the true phrenologist infers from a large braincase or cranium a large brain within it, and from that fact, in accordance with the observations of all comparative anatomists on the cerebral hemispheres of man, and what we with great self-complacence term the lower animals-he also infers, cæteris paribus, greater mental power, for it is no less true of nervous than it is of muscular tissue, that quantity is the external sign of power. That the phrenologist also assumes that he can, from differences in the local growth of brain, infer greater aptitude for certain kinds of mental activity is quite true, and it is only when he draws these inferences that he steps beyond the path of the mere physiologist; but these special inferences do not affect the main principle one jot, that size of brain is, cæteris paribus, an indication of mental power. It only enables him to indicate the kind of mental activity a given brain is likely to be capable of.

THE HARMONIOUS BLACKSMITH.

The physiologist who infers from the muscular development of Mr. Strong-in-the-arm that he can exert great force does not presume to say on what kind of labour that force is habitually exerted; he never says of one, this is an oarsman-of another, this man is accustomed to use the plane and the saw, or to wield the axe or blacksmith's sledge hammer, or that he is a miner or artilleryman, but simply that his arms fit him for the various labours of persons engaged in such labours as I have enumerated; and he can do this as well blindfolded as with his eyes open. So likewise can the phrenologist manipulate and judge the heads of the people as well with his eyes shut as with them open; but there is all the difference between judging the kind of work a given head is likely to be capable of doing, and determining the specific work it habitually does. This is as far beyond the province of phrenology as it is beyond the ability of a stranger to the individual whose pericranium is undergoing manipu lation, and to expect it of the former is about as reasonable as to expect it of the latter, for he obviously cannot determine by the mere external form of a braincase whether it belonged to a poet or a philosopheran author or an editor-although, if his eyes are Brinsmead leaves the early history of the manufacture of the piano in England just where he found it thoroughly open," and artistically educated, it might i.e., in outer darkness; he throws no light on it what-not, from his peculiar physiognomy, be quite impossible to distinguish the latter from the former, for ever. More than thirty-five years ago, my old friend Minerva herself-although feminine and strong-minded, Joseph Kirkman, Esq., said that not only had it not even if she wore ringlets or a chignon (which is not then been written, but that he much doubted if any on record in Rollin)-could hardly have had the assurone survived, even at that long past time, excepting ance to ape the ambrosial curls of Olympian Jove. himself, who combined a memory extending back into the last century, with access to authorities in the archives of so old a firm as his own. He then promised to write his history, but has not yet done so, and I fear never will. Rimbault collected a great deal of information concerning keyed instruments in use anterior to the piano, but no very great amount of undisputed facts concerning its early manufacture in England, and this subject continues in "outer darkness." Of course, as usual, we are told all the early specimens of English manufacture were grands. It may well be so, for Fulke Greville's pianos were all most certainly of this form, just as the earliest of continental manufac. ture of which we have any record, viz., Christofali's, is a hammer harpsichord, i.e., an imperfect grand piano. Strange to say we have squares considerably older than any grand known to exist of English make, for the earliest or rather its name board, the instrument itself is lost-bears the name of Americus Backers, fecit A.D. 1776. Messrs. Tschudi, Broadwood, & Co. did not commence to make grands until 1781, but they sold squares ten years before that time. I strongly suspect they or Robert Stodart, perhaps in conjunction with Backers, made the first grand piano, properly so called, produced in England; I mean an instrument with hainmers only, not hammers added to jacks, for although the addition of hammers really converted the harpsichord into an instrument capable of expression, which were commonly termed harpsichords on which you can play piano and forte, harpsichord being yet the principal or leading name of the instrument; and it seems probable the Americus Backers (of which we only have the name board) may have been one of this kind. THE HARMONIOUS BLACKSMITH.

PHRENOLOGY.

[133] SIR,-For so "'umble" a correspondent, as lowly as a mere blacksmith, to give utterance to opinions differing from those of so august, sublime, and sage a personage as an editor seems almost lese majesty; but, just as the "slaves" of old Rome had their Saturnalia, so your humblest of slaves would, although in abject fear of your whip, exercise a similar license by asking if you were not lately just a leetle hard on the poor phrenologists, when you triumphantly enquired if they were able to distinguish astronomers from gastronomers, pocts from parsons, engineers from enginedrivers, or solicitors from surgeons-in a word, the profession of the "party" whose pericranium they manipulate blindfolded; and whether this is not rather too much to ask?

Without committing myself to the acknowledgment of belief in all so-called phrenologists have put forth, I may just say that I believe the foundations of this so-called science-which, after all, is only one division of human physiology-are well-ascertained physiological facts; for what scientific physiologist can dispute that fundamental one that, cæteris paribus, size is the almost universal external indication of power both of nervous and muscular tissue.

When we see a man's arm of great girth, and we find its muscles hard and healthy, we feel perfectly justified in inferring that it is capable of exerting great force;

IRON IN BATTERIES.

[134] SIR, -Your correspondent, Thomas C. Haines, says he is inclined to think that iron has not received much attention as a positive element in a battery. I beg to inform him that it is well known that iron stands next to zine in the list of electro-positive metals, zine being the highest of the two. Many use zinc and iron for a galvanic battery. When such is used cast iron is the best, because out of every 100 parts of common cast iron sixty-five parts are carbon and This explains how cast iron thirty-five parts iron. The reason, I stands so electro-negative to zinc. believe, why iron is not so much used in the galvanic battery, though being highly electro-positive to copper, carbon, &c., is because it is acted upon so furiously by acids, and not an easy metal to amalgamate; though cheap in the first place, it is dear in the end.

A. J. JARMAN.

MODUS OPERANDI. [135] SIR, Does "Xenophon" (1270) wish for the simplest mode of obtaining the metal from a If so, the best mixture of the oxides, &c., he names? and simplest mode would be to distil with an excess of potassiuin. The sodium will distil over pure, and fused magnesium remain behind with the unaltered potassic hydrate.

The simplest mode of obtaining magnesinm from its hydrate is to fuse it with sodium. The best way, though, is to first convert it into the double chloride of ammonium and magnesium and then fuse with sodium. Sodium is obtained from its carbonate-most simply by distilling with potassium, most economically by converting it into the tartrate, mixing with charcoal and distilling. Four ounces of sodic carbonate by this means will yield one and a half ounce of sodium. Potassium is obtained most simply by distilling at a white heat the oxide, or hydrate rather, with carbon, or else by decomposing by a powerful battery. It is most easily prepared by igniting the tartrate with charcoal and distilling at a bright red heat. of potassic hydrate will yield little more than one of potassium.

Six ounces

A porcelain incased graphite crucible will prove most durable for such work, and will, I think, best

suit "A Student" (4272).

If "J." (4285) will apply to Griffin's they will doubtlessly furnish him with a detailed description with illustrations of their gas furnace, which by a little manipulation is readily converted into mutile furnace of a very superior description. It uses from 20 to 200 cubic feet per hour, as may be needed.

E. H. (4298.) Chloride of silver turns blue from deURBAN. composition.

P. S.-One of your correspondents wishes to know the date of the Metrical Act. From a copy of the standard measures of this commission, printed for private use of the members, I find it to be known as 1864, the year of the commission.

Effective pressure by calculation .. 10lb. 14oz.

dynamometer 10lb. 80z. The second was a tapered lever of the following dimensions-viz., length, 22in.; distance from the fulcrum to the centre of the valve, 2.75in.; breadth of the lever of the fulcrum, 1'5in.; breadth at the end in.; and weight, 4lb. 2oz.

The only thing to be observed in calculating the effective pressure of a tapered lever is, to diminish the half of the lever by the difference of the taper. 1in. - Jin. gin... 11in. gin. 10ğin, or 10-875in. 2-750) 10-375 (3·772 = ratio of the two arms 8250

see

=

21250

19250

20000

19250

7500

5500

3.772

==

ratio of the two arms. 4.125 = weight of lever.

that a continuous discharge of artillery will draw rain
in cloudy weather. Many military men have noticed
this, and it is well known that many of our modern
battles have terminated in a deluge of rain, as
Waterloo. Long practice of artillery has been known,
even in India, frequently to draw rain; and it has been
remarked that the practice of our Volunteer Artillery
is often followed by a rainy evening.

It was so

My attention was particularly called to this fact upon
the occasion of the Sultan's visit to this country.
Wherever he went he was followed by rain.
when he went to the City-to the review at Spithead-|
and especially to that at Wimbledon, where he sat on
horseback in drenching rain-although not a drop had
fallen until the rounds of artillery, which announced
his arrival, had been discharged. I wrote a letter for
insertion in the Times, with a view to draw attention to
this matter, being confident that if our men of science,
who have accomplished such wonders in other direc-
tions, could be induced to take it up, something would
be done for our relief. My letter was dated Wednes-
day, the 15th ult., and in it I asked whether an explo
sion of gunpowder would produce the same effect as
the firing of artillery. The editor did not think my
letter worth publishing, but the question I asked was
answered the following day by the explosion of the
Government Powder Mills, at Waltham Abbey, which
was followed, as is well known, by some hours of rain,
extending into the surrounding counties. Such an
explosion would certainly cause a concussion of the
atmosphere, which-drawing the clouds together
would produce thunder and lightning, and rain; and
did so on this occasion, reaching in a circle as far as
150 miles from the scene of the disaster. We all know
what a ripple or wave will reach the shore when even a
small stone is thrown into a pond. And if, as I have
heard, the firing of a gun will cause a dead body, hid at
the bottom of a pool, to rise to the surface, I can well
believe that the explosion of gunpowder may cause rain
to fall from clouds passing over us, which otherwise
would empty themselves into the German Ocean.

If the insertion of this letter in your valuable paper
will draw the attention of the right men to this subject,
I believe agriculturists, all over England, will be
greatly your debtors.

ELLIPSOGRAPH.

R. P.

[140] SIR,-Since last I wrote on this subject I have roughly tried each of the plans shown above, and with

F

..

FIG. 2

dynamometer 15lb. 4oz.
THOMAS J. O'Connor.

D

E

LATHE CONSTRUCTION.-TO "J. K. P." [138] SIR,-I hail the arrival of your most comprehensive journal as one of the greatest pleasures of the week, and must add my testimony to the zeal and ability with which it is now conducted. I did oncegive it up, when I found proposals for emptying leaking ships by a syphon seriously entertained, and other childish matters filling up valuable space, Mais nous changé cela. I have derived great benefit from the various papers on lathe construction, and I would endorse your correspondent's request that some such proficient as "J. K. P." should give a complete description, illustrated with working drawings, of a lathe which combines all the latest improvements.

avous

with the connecting rod Gin. long, is equal to
6 × 422 or 2.53in., which will be right for projecting
circles in isometrical drawing. I think the easiest
guide to make for the end E would be as I have drawn
it, with a small roller kept in contact with a short
straight-edge by means of an elastic band. I have
shown the base-piece as made, of sheet iron about
1-12in. thick, with a gap in the middle and feather
edges to place on one axis of ellipse, and a broad
arrow to be brought into contact with the other.

that I only referred to it in order that we might get at the real state of the case, and did not wish to follow that part of the subject, observing that in doing this we must expect objections from parties that were interested in the existing gas companies.

I am glad to see that I have helped to ventilate this important subject, but I certainly felt not a little sur prised to find (p. 870 of your number for the oth inst.) our well-known and valued contributor" Sigma,” indulging in rather discourteous language in his critique on my letter.

I little thought that we should have to class him amongst the interested parties from whom we must be prepared for objections in our attempts to reduce our gas bills, and had he advanced any scientific facts or argements against my statements I am sure that all your readers, including myself, would have felt much obliges to him for such, as we already are for his valuable articles upon "Electricity," &c., &c., which I am sure are resi with deep interest and attention by thousands of my fellow subscribers to the ENGLISH MECHANIC.

But I fear our talented electrician has rather lost temper upon my having unknowingly trod on "tender corn," and that he has written rather hastily about " gas."

I do not think your readers will care much to know what he or I think of each other's knowledge about gas, nor do I wish to fill your valuable space with personal dispute, but as "Sigma" distinctly charges ine with making "misleading statements," he is bound to prove such a sweeping and dogmatic assertion; but he does not do this, for the rest of his letter goes, in fact, to confirm what I stated regarding the extraction of the hydrocarbon vapours from the gas in the course of manufacture; but he does not tell us what is most undoubtedly a fact-viz., that the illuminating power of the gas is lowered thereby.

I could add much on this point, and show that Sigma" has kept back part of the truth in his desire to "burk" the subject, by talking about "false statements" and gas quacks, &c., which is rather strong language; but as the whole subject of " gas-making" is to be found fully explained in any of the good works upon practical chemistry, and all the tricks and dodges have been often exposed, it is no nse ** Sigma," or "any other man," trying to throw dust in our eyes. And if he classes such writers as Letheby, Frankland, Defries, Renton, and others as gas quacks, because they have proved the doings of the gas companies to be open to remark, I shall be proud to be called a gas quack too.

It is very well known that a ton of coal will yield gas, differing in quality and in quantity, according to the manner in which it is treated in the retorts-in the one case giving off a fine and brilliant gas of less quantity; and in the other case producing a larger quantity, but of very inferior gas, of which the consumers are obliged to use more to obtain requisite light, and thus our gas bills are found to get heavier, and the public suffer.

The concluding part of " Sigma's" letter is really very rich indeed, for while he tells us it is our own fault that the price of gas is so high, he takes care not to admit the fact of the handsome dividends that have been paid to the shareholders, and of the boss in addition, to avoid the letter of the law, which restricts their dividing a higher dividend.

hand way in which the question of carburetting gis I do not think that I need take any notice of the offalso disposed of. Let your readers try, and they l soon find "facts are stubborn things," and worths host of such sneers, which are so evidently prejudiced that they will go for nothing with all reflecting

tained the best carboline or carburine from Messrs. In reply to the second question, I have always ob The lower, Fig. 2, would probably be the best for Woodward & Co., 2, Mint-street, Borough, S.E. It is simply light naphtha with unextracted benzole, obshowing the ellipses for this purpose, as the half ex-tained from coal tar, or shale. Messrs. Carless and hibited is generally all on one side of the major axis, and in this plan the two halves of that half match each other, or are symmetrical, while in Fig. 1, the oval is symmetrical about the major, and not the minor axis. In case of the whole ellipse being required it might be drawn half at a time, first on one side of axis, and then reversing the instrument, for the other half, or better still the whole struck in from both sides, and the mean of the two taken with a French curve. scarcely be necessary, however, except with a short connecting rod, or with the largest ovals that the instrument will take in. I have drawn the connecting rod only four times the length of the ellipse shown, and Fig. 1 is quite equal to drawing one of 24in. long. The gap is much deeper than necessary, as I have made it semicircular, which it has to be in any other instruThese things could be turned out very cheap, and I should think would pay an instrument maker to H. D. C., Capt. R. E. bring out. The base of Fig. 2 would have to be something like a capital Y, and would be made of wood.

[142] SIR,-Will you kindly allow me space for a few lines by way of a reply to Mr. Grierson's remarks respecting the comparative merits of Lewis's and Pitman's systems? I am a writer of Pitman's phonography, and, notwithstanding all the "complications" of which Mr. Grierson speaks, I completely mastered the system in about nine months, without more than three hours practice per week during the whole time.

I think it is unfair for Mr. Grierson to quote from the 11th edition of Phonography, in his endeavours to prove its inferiority to Lewis's system, for if his only object be to direct "Hermit" to the best system of shorthand he should make a comparison between Lewis's system and phonography as it is rather than as it was; though I by no means admit that the 11th edition of Phonography was in any respect inferior to Lewis's system.

As I do not desire to trespass largely on your space, I will at once proceed to review Mr. Grierson's remarks on the vowel scale of the system. He objects to the

[143] SIR, AS Mr. Grierson (page 400) invites corrections and criticisms, will you allow me to state hat he ought not to have quoted from the "Phono-priate"? raphic Teacher," which is only for learners, but from Manual," where he would have found seventy. ve "grammalogues, or letter-words," for ordinary use, nd about 300 for reporting. This, I think, pats Lewis's 108 contractions into the shade. Mr. G. -rings up all his old arguments against Pitman's ystem-such as the number of different positions for The vowels, &c. It is quite a sufficient answer to all his to say that the alleged difficulties exist only in your correspondent's imagination.

Phonographers themselves do not complain. I am sure that amongst the "cloud of witnesses" who have written to our Editor in defence of Pitman, there will not be found one complaint on any of the points stated by Mr. G. We are also told that Lewis's system is as phonetic as Pitman's. This is not the case. Pitman's is the only system which is phonetic in the true sense of the word. Lewis's, in company with all other stenographic methods, is just as much phonetic as our A B C alphabet, and no more. Mr. G. ridicules Pitman for giving a character to the sound ZH. It is sufficient to say that the sound exists in the English language, and therefore no phonetic alphabet would be complete without a corresponding sign. If Lewis's alphabet is phonetic, where is his sign for ZH ?

There are two descriptions of bore in common use; one is called the conical bore, that is, the interior of the instrument gradually increases in diameter from the smallest end to the top of the middle joint, the head being cylindrical. The other is termed the cylindrical bore (the same as the clarionet). On this system the instrument is of the same diameter from the lowest part to the top of the middle joint, and the head coniIn comparing different systems of shorthand, three cal, decreasing upwards. The bore of the Equisonant grand features ought not to be overlooked-brevity, flute differs from both of the above for the following speed, and legibility. And I contend that on all these reasons:-Taking the human voice for a model, it will 13 hree points phonography carries off the palm. As be found that every different sound has a different size regards brevity, it has been found that the average or diameter of the larynx. Musical instruments are number of strokes required to write a word in phono- based upon the same principle-for instance, the pipes graphy is one and a quarter. As regards speed, it is of an organ are gradually shortened in the ascending how generally admitted that the resources of phono-scale, but the mere act of shortening is not sufficient,