Chapter I: II. III. IV (4)

Another mode of communicating intelligence secretly, viz. to agree upon some printed book, and mark the words out, is also troublesome, and not at all safe. The method of concealing the words which are to convey the information intended in matter of a very different character, in a long letter which the correspondent is enabled to read by applying a paper to it, with holes corresponding to the places of the significant words, is attended with many disadvantages: the paper may be lost, the repetition of certain words may lead to a discovery, and the difficulty of connecting the important with the unimportant matter, so as to give to the whole the appearance of an ordinary letter, is considerable.

There are many kinds of sympathetic inks. They are so called because the writings or drawings made by them are illegible, till by the action of some chemical agents, such as light, heat, acids, or other substances are brought in contact with them, when they appear. A weak sulphate of iron will be invisible in writing till washed over with a weak solution of prussiate of potass, which turns it of a beautiful blue. If we write with the nitro-muriate of gold, and afterwards brush the letters over with dilute muriate of tin, the writing will appear of a beautiful purple. If we write with a diluted solution of muriate of copper, and when dry present it to the fire, it will be of a yellow color.

Chemistry was also in great request for secret writing, and various substances were found to afford a fluid which would leave no mark behind the pen, until some chemical agent were applied. For example, if a letter be written with a pen dipped in the juice of lemon, the words will be invisible until the paper is held before the fire. This is caused by the action of the heat. Again, if a solution of nitrate of iron be the fluid used, the writing cannot be seen until it is dipped into a solution of galls, or even into tea, which will act upon the iron, and become ink. It was found that if a plain sheet of paper were sent, and intercepted, the very fact of its being plain rendered it suspicious, and every means were used to render visible any writing that might be on it. A letter was therefore written with ordinary ink, on indifferent subjects, and between the lines the required information was added in some sympathetic ink. But writing with these or other sympathetic inks is unsafe, because the agents employed to render them visible are too generally known. Hence, the chiffre indéchiffrable, as it is called, has come very much into use, because it is easily applied, difficult to be deciphered, and the key may be preserved in the memory and easily changed. It consists of a table in which the letters of the alphabet, or any other signs agreed upon, are arranged as follow:

z a b c d e f g h i k l m n o p q r s t u v w x y z
a b c d e f g h i k l m n o p q r s t u v w x y z a
b c d e f g h i k l m n o p q r s t u v w x y z a b
c d e f g h i k l m n o p q r s t u v w x y z a b c
d e f g h i k l m n o p q r s t u v w x y z a b c d
e f g h i k l m n o p q r s t u v w x y z a b c d e
f g h i k l m n o p q r s t u v w x y z a b c d e f
g h i k l m n o p q r s t u v w x y z a b c d c f g
h i k l m n o p q r s t u v w x y z a b c d e f g h
i k l m n o p q r s t u v w x y z a b c d e f g h i
k l m n o p q r s t u v w x y z a b c d e f g h i k
l m n o p q r s t u v w x y z a b c d e f g h i k l
m n o p q r s t u v w x y z a b c d e f g h i k l m
n o p q r s t u v w x y z a b c d e f g h i k l m n
o p q r s t u v w x y z a b c d e f g h i k l m n o
p q r s t u v w x y z a b c d e f g h i k l m n o p
q r s t u v w x y z a b c d e f g h i k l m n o p q
r s t u v w x y z a b c d e f g h i k l m n o p q r
s t u v w x y z a b c d e f g h i k l m n o p q r s
t u v w x y z a b c d e f g h i k l m n o p q r s t
u v w x y z a b c d e f g h i k l m n o p q r s t u
v w x y z a b c d e f g h i k l m n o p q r s t u v
w x y z a b c d e f g h i k l m n o p q r s t u v w
x y z a b c d e f g h i k l m n o p q r s t u v w x
y z a b c d e f g h i k l m n o p q r s t u v w x y
z a b c d e f g h i k l m n o p q r s t u v w x y z

Any word is now taken for a key. The word _Paris_, for example. This is a short word, and for the sake of secresy it would be well to choose for the key some one or more words less striking. Suppose we wish to write in this cypher with this key the phrase, "We lost a battle," we must write _Paris_ over the phrase, repeating it as often as is necessary, thus:

Pa risP a risPar
We lost a battle.

We now take cypher for _w_, the letter which we find in the square opposite _w_ in the left margin column, and under _p_ on the top, which is _m_. Instead of _e_ we take the letter opposite _e_, and under _a_, which is _f_; for _l_, the letter opposite _c_, and under _z_, and so on.

Proceeding thus, we should obtain the following series of letters:

mf cxli b tkmimw

The person who receives the epistle writes the key over the letters

P a r i s P a r i s P a r
m f c x l i b t k m i m w

He now goes down in the perpendicular line, at the top of which is _p_, until he meets _m_, opposite to which, in the left marginal column, he finds _w_. Next, going in the line of _a_ down to _f_ he finds, on the left, _e_. In the same way _r_ gives _l_, _i_ gives _o_, and so on. Or you may reverse the process; begin with _p_, in the left marginal column, and look along horizontally till you find _m_, over which, in the top line, you will find _w_. It is easily seen that the same letter is not always designated by the same cypher; thus _e_ and _a_ occur twice in the phrase selected, and they are designated respectively by the cyphers _f_ and _w_, _b_ and _k_. Thus the possibility of finding out the secret writing is almost impossible.

The key may be changed from time to time, and a different key may be used with each correspondent. The utmost accuracy is necessary, because one character accidentally omitted changes the whole cypher. The best way of determining the key word is to arrange that any word which occurs at a certain distance from the beginning or end shall be the key word--the tenth from the beginning, for example. The key word will thus change every time, and any combination of letters will make it. This will make it impossible to be guessed.

The easiest method of working this square is to cut a piece of thin wood like a carpenter's square, and by applying it to the alphabet the letter is at once seen in the angle. For example, supposing such a square to be applied so that one side is on the letter _p_ at the top, and the other on the letter _w_ at the left hand, the letter _m_ will be in the angle, so that the trouble of following the lines with the eye will be avoided.

Here is another specimen of secret writing.

A LOCK FOR MR. HOBBS TO PICK.

T:2 21rt:(,)t:2 s21(,)t:2 st1rr6 s,6(,)
1r2 86p : 2rs wr3t 76 : 1-9 93v3-2(,)
T : 1t : 1-9 w:38: t5-29 t:23r : 1r ? 4-6(,)
1-9 7192 t:23r v1r329 .!4r325 s:3-2(:)
3- t:2? 22- :21t:2-s 262 ?16 s22
S6?74!s 3- 5-2 .r1-9 tr3t: 84?75-2(;)
76t 3- t:2 744, 40 744,s t:2r2 !32s
1 ,26 34 r219 t:23r ?6st2r32s (.)

T:2- !2t -4t 013t:!2ss t4-.52 19v1-82
3ts s:1!!4w v15-ts(,)-4r s84002r 91r2
5p4- t:2 71sl2 40 3.-4r1-82
T4 r13s2 1 str58t5r2 40 92sp13r(!)
T:45.: 044!s ?16 .3v2 t:2 w4r!9s t4 8:1-82(,)
92s3.- 1-9 pr4v392-82 1r2 t:2r2(.)
:4w 7!3-929(,)w:4 1t 921t: 1!4-2
T:23r 922p s3.-30381-86 4w-(!)

HERE IS THE ANSWER.

The letters are represented by the figures and symbols below them. With this key the lock may be opened.

a b c d e f g h i j k l m n o u y
1 7 8 9 2 0 . : 3 ; , ! ? - 4 5 6

The stops enclosed in brackets, are used in their capacity of stops: thus, (,) (;) &c.

The earth, the sea, the starry sky,
Are cyphers writ by hand divine,
That hand which tuned their harmony,
And bade their varied glories shine;
In them e'en heathen's eye may see
Symbols in one grand Truth combine;
But in the book of books there lies
A key to read their mysteries.

Then let not faithless tongue advance
Its shallow vaunts, nor scoffer dare
Upon the base of ignorance
To raise a structure of despair!
Though fools may give the world to chance
Design and Providence are there:
How blinded, who at death alone
Their deep significancy own!

THE CIRCULAR CYPHER.

To carry on a correspondence without the possibility of the meaning of the letter being detected, in case it should be opened by any other person, has employed the ingenuity of many. No method will be found more effectual for this purpose, or more easy, than the following.

Provide a piece of square card or pasteboard, and draw a circle on it, which circle is to be divided into 27 equal parts, in each of which parts must be written _one_ of the capital letters of the alphabet, and the &, as in the figure. Let the center of this circle be blank. Then draw another circle, also divided into 27 equal parts, in each of which write one of the small letters of the alphabet, and the &. This circle must be cut round, and made exactly to fit the blank space in the center of the large circle, and must run round a pivot or pin. The person with whom you correspond must have a similar dial, and at the beginning of your letter you must put the capital letter, and at the end the small letter, which answer to each other when you have fixed your dial.

Suppose what you wish to communicate is as follows:

_I am so watched I cannot see you as I promised; but I will meet you to-morrow in the park, with the letters, &c._

You begin with the letter _T_, and end with the letter _m_, which shows how you have fixed the dial, and how your correspondent must fix his, that he may decipher your letter. Then, for _I am_, you write _b uf_, and so of the rest, as follows:

_T b uf lh pumwayx b wugghm lyy rhn ul b ikhfblyx vnm b pbee fyym
rhn mh fhkkhp bg may iukd pbma may eymmykl, tw._

_m._

_Another Way._

Take two pieces of card, pasteboard, or stiff paper, through which you cut long squares at different distances. One of these you keep yourself, and the other you give to your correspondent. You lay the pasteboard on a paper, and, in the spaces cut out write what you would have understood by him only; then fill the intermediate spaces with any words that will connect the whole together, and make a different sense. When he receives it, he lays his pasteboard over the whole, and those words which are between crotchets [ ] form the intelligence you wish to communicate. For example: suppose you want to express these words,

"_Don't trust Robert: I have found him a villain._"

"[Don't] fail to send my books. I [trust] they will be ready when [Robert] calls on you. [I have] heard that you have [found] your dog. I call [him a villain] who stole him." You may place a pasteboard of this kind three other ways--the bottom at top--the top at bottom, or by turning it over; but in this case you must previously apprize your correspondent, or he may not be able to decipher your meaning.

SECRET CORRESPONDENCE BY MUSIC.

Form a circle like Fig. 2, divided into twenty-six parts, with a letter of the alphabet written in each. The interior of the circle is movable, like that in Fig. 1, and the circumference is to be ruled like music paper. Place in each division a note different in figure or position.

Within the musical lines place the three keys, and on the outer circle the figures to denote time. Then get a ruled paper, and place one of the keys (suppose _ge-re-sol_) against the time 2-4ths, at the beginning of the paper, which will inform your correspondent how to place his circle. You then copy the notes that answer to the letters of the words you intend to write, in the manner expressed above.

THE MAGIC OF STRENGTH.

"Not two strong men the enormous weight could raise,
Such men as live in these degenerate days."--POPE'S HOMER.

The mechanical knowledge of the ancients was principally theoretical; and though they seem to have executed some minor pieces of mechanism which were sufficient to delude the ignorant, yet there is no reason for believing that they have executed any machinery that was capable of exciting much surprise, either by its ingenuity or its magnitude. The properties of the mechanical powers, however, seem to have been successfully employed in performing feats of strength which were beyond the reach even of strong men, and which could not fail to excite the greatest wonder when exhibited by persons of ordinary size.

Firmus, a native of Seleucia, who was executed by the Emperor Aurelian for espousing the cause of Zenobia, was celebrated for his feats of strength. In his account of the life of Firmus, who lived in the third century, Vopiscus informs us that he could suffer iron to be forged upon an anvil placed upon his breast. In doing this, he lay upon his back, and, resting his feet and shoulders against some support, his whole body formed an arch, as we shall afterward more particularly explain. Until the end of the sixteenth century, the exhibition of such feats does not seem to have been common. About the year 1703, a native of Kent, of the name of Joyce, exhibited such feats of strength in London and other parts of England, that he received the name of the second Samson. His own personal strength was very great; but he had also discovered, without the aid of theory, various positions of his body in which men even of common strength could perform very surprising feats. He drew against horses, and raised enormous weights; but as he actually exhibited his powers in ways which evinced the enormous strength of his own muscles, all his feats were ascribed to the same cause. In the course of eight or ten years, however, his methods were discovered, and many individuals of ordinary strength exhibited a number of his principal performances, though in a manner greatly inferior to Joyce.

Some time afterward, John Charles Van Eckeberg, a native of Harzgerode, in Anhault, traveled through Europe under the appellation of Samson, exhibiting very remarkable examples of his strength. This, we believe, is the same person whose feats are particularly described by Dr. Desaguliers. He was a man of the middle size, and of ordinary strength; and as Dr. Desaguliers was convinced that his feats were exhibitions of skill, and not of strength he was desirous of discovering his methods, and, with this view, he went to see him, accompanied with the Marquis of Tullibardine, Dr. Alexander Stuart, Dr. Pringle, and his own mechanical operator. They placed themselves round the German, so as to be able to observe accurately all that he did, and their success was so great, that they were able to perform most of the feats the same evening by themselves, and almost all the rest when they had provided the proper apparatus. Dr. Desaguliers exhibited some of the experiments before the Royal Society, and has given such a distinct explanation of the principles on which they depend, that we shall endeavor to give a popular account of them.

1. The performer sat upon an inclined board A B, placed upon a frame C D E, with his feet abutting against the upright board C. Round his loins was placed a strong girdle FG, to the iron ring of which at G was fastened a rope by means of a hook. The rope passed between his legs through a hole in board C, and several men, or two horses, pulling at the other end of the rope, were unable to draw the performer out of his place. His hands at G seemed to pull against the men, but they were of no advantage to him whatever.

2. Another of the German's feats is shown in Fig. 2. Having fixed the rope above mentioned to a strong post at A, and made it pass through a fixed iron eye at B, to the ring in his girdle, he planted his feet against the post at B, and raised himself from the ground by the rope, as shown in the figure. He then suddenly stretched out his legs and broke the rope, falling back on a feather bed at C, spread out to receive him.

3. In imitation of Firmus, he laid himself down on the ground, as shown in Fig. 3, and when an anvil A was placed upon his breast, a man hammered with all his force the piece of iron B, with a sledge hammer, and sometimes two smiths cut in two with chisels a great cold bar of iron laid upon the anvil. At other times a stone of huge dimensions, half of which is shown at C, was laid upon his belly, and broken with a blow of the great hammer.

4. The performer then placed his shoulders upon one chair, and his heels upon another, as in Fig. 4, forming, with his back-bone, thighs, and legs, an arch springing from its abutments at A and B. One or two men then stood upon his belly, rising up and down while the performer breathed. A stone, one and a half feet long, one foot broad, and half a foot thick, was then laid upon his belly and broken by a sledge hammer, an operation which may be performed with much less danger than when his back touched the ground, as in Fig. 3.

5. His next feat was to lie down on the ground, as in Fig. 5. A man being then placed on his knees, he draws his heels towards his body, and, raising his knees, he lifts up the man gradually, till, having brought his knees perpendicularly under him, as in Fig. 6, he raises his own body up, and, placing his arms around the man's legs, he rises with him, and sets him down on some low table or eminence of the same height as his knees. This feat he sometimes performed with two men in place of one.

6. The last, and apparently the most wonderful, performance of the German, is shown in Fig. 7, where he appears to raise a cannon A, placed upon a scale, the four ropes of the scale being fixed to a rope or chain attached to his girdle, in the manner already described. Previous to the fixing of the ropes, the cannon and scale rest upon two rollers B C, but when all is ready, the two rollers are knocked from beneath the scale, and the cannon is sustained by the strength of his loins.

The German also exhibited his strength in twisting into a screw a flat piece of iron like A, Fig. 8. He first bent the iron into a right angle, as at B, and then wrapping his handkerchief about its broad upper end, he held that end in his left hand, and with his right applied to the other end, twisted about the angular point, as shown at C. Lord Tullibardine succeeded in doing the same thing, and even untwisted one of the irons which the German had twisted.

It would lead into details by no means popular, were I to give a minute explanation of the mechanical principles upon which these feats depend. A few general observations will perhaps be sufficient for ordinary readers. The feats No. 1, 2, and 7, depend entirely on the natural strength of the bones of the pelvis, which form a double arch, which it would require an immense force to break, by any external pressure directed to the center of the arch; and, as the legs and thighs are capable of sustaining four or five thousand pounds when they stand quite upright, the performer has no difficulty in resisting the force of two horses, or of sustaining the weight of a cannon weighing two or three thousand pounds.

The feat of the anvil is certainly a very surprising one. The difficulty, however, really consists in sustaining the anvil; for when this is done, the effect of the hammering is nothing. If the anvil were a thin piece of iron, or even two or three times heavier than the hammer, the performer would be killed by a few blows; but the blows are scarcely felt when the anvil is very heavy, for the more matter the anvil has, the greater is its inertia, and it is the less liable to be struck out of its place; for when it has received by the blow the whole momentum of the hammer, its velocity will be so much less than that of the hammer, as its quantity of matter is greater. When the blow, indeed, is struck, the man feels less of the weight of the anvil than he did before, because, in the reaction of the stone, all the parts of it round about the hammer rise towards the blow. This property is illustrated by the well known experiment of laying a stick with its ends upon two drinking glasses full of water, and striking the stick downwards in the middle with an iron bar. The stick will in this case be broken without breaking the glasses, or spilling the water. But if the stick is struck upwards, as if to throw it up in the air, the glasses will break if the blow be strong, and if the blow is not very quick, the water will be spilled without breaking the glasses.

When the performer supports a man upon his belly, as in Fig. 4, he does it by means of the strong arch formed by his backbone, and the bones of his legs and thighs. If there were room for them, he could bear three or four, or, in their stead, a great stone to be broken with one blow.

A number of feats of real and extraordinary strength were exhibited about a century ago, in London, by Thomas Topham, who was five feet ten inches high, and about thirty-one years of age. He was entirely ignorant of any of the methods for making his strength appear more surprising; and he often performed, by his own natural powers, what he learned had been done by others by artificial means. A distressing example of this occurred in his attempt to imitate the feat of the German Samson by pulling against horses. Ignorant of the method which we have already described, he seated himself on the ground with his feet against two stirrups, and by the weight of his body he succeeded in pulling against a single horse; but in attempting to pull against two horses, he was lifted out of his place, and one of his knees was shattered against the stirrups, so as to deprive him of most of the strength of one of his legs. The following are the feats of real strength which Dr. Desaguliers saw him perform.

1. Having rubbed his fingers with coal-ashes to keep them from slipping, he rolled up a very strong and large pewter plate.

2. Having laid seven or eight short and strong pieces of tobacco-pipe on the first and third fingers, he broke them by the force of his middle finger.

3. He broke the bowl of a strong tobacco-pipe placed between his first and third fingers, by pressing his fingers together sideways.

4. Having thrust such another bowl under his garter, his legs being bent he broke it to pieces by the tendons of his hams, without altering the bending of his leg.

5. He lifted with his teeth, and held in a horizontal position for a considerable time, a table six feet long, with half a hundred weight hanging at the end of it. The feet of the table rested against his knees.

6. Holding in his right hand an iron kitchen poker three feet long and three inches round, he struck upon his bare left arm, between the elbow and the wrist, till he bent the poker nearly to a right angle.

7. Taking a similar poker, and holding the ends of it in his hands, and the middle against the back of his neck, he brought both ends of it together before him, and he then pulled it almost straight again. This last feat was the most difficult, because the muscles which separate the arms horizontally from each other are not so strong as those which bring them together.

8. He broke a rope about two inches in circumference, which was partly wound about a cylinder four inches in diameter, having fastened the other end of it to straps that went over his shoulder.

9. Dr. Desaguliers saw him lift a rolling stone of about 800 pounds' weight with his hands only, standing in a frame above it, and taking hold of a frame fastened to it. Hence Dr. Desaguliers gives the following relative view of the strengths of individuals:

Strength of the weakest men, 125 pounds.
Strength of very strong men, 400
Strength of Topham, 800

The weight of Topham was about 200.

One of the most remarkable and inexplicable experiments relative to the strength of the human frame, which we have ourselves seen and admired, is that in which a heavy man is raised with the greatest facility, when he is lifted up the instant that his own lungs, and those of the persons who raise him, are inflated with air. This experiment was, I believe, first shown in England a few years ago by Major H., who saw it performed in a large party at Venice under the direction of an officer of the American navy. As Major H. performed it more than once in my presence, I shall describe, as nearly as possible, the method which he prescribed. The heaviest person in the party lies down upon two chairs, his legs being supported by the one and his back by the other. Four persons, one at each leg and one at each shoulder, then try to raise him, and they find his dead weight to be very great, from the difficulty they experience in supporting him. When he is replaced in the chairs, each of the four persons takes hold of the body as before, and the person to be lifted gives two signals by clapping his hands. At the first signal he himself and the four lifters begin to draw a long and full breath, and when the inhalation is completed, or the lungs filled, the second signal is given, for raising the person from the chairs. To his own surprise and that of his bearers, he rises with the greatest facility, as if he were no heavier than a feather. On several occasions I have observed that when one of the bearers performs his part ill, by making the inhalation out of time, the part of the body which he tries to raise is left, as it were, behind. As we have repeatedly seen this experiment, and have performed the part both of the load and of the bearer, we can testify how remarkable the effects appear to all parties, and how complete is the conviction, either that the load has been lightened, or the bearer strengthened by the prescribed process.

At Venice, the experiment was performed in a much more imposing manner. The heaviest man in the party was raised and sustained upon the points of the fore fingers of six persons. Major H. declared that the experiment would not succeed if the person lifted were placed upon a board, and the strength of the individuals applied to the board. He conceived it necessary that the bearers should communicate directly with the body to be raised. I have not had an opportunity of making any experiments relative to these curious facts; but whether the general effect is an illusion, or the result of known or of new principles, the subject merits a careful investigation.

Among the remarkable exhibitions of mechanical strength and dexterity, we may enumerate that of supporting pyramids of men. This exhibition is a very ancient one. The simplest form of this feat consists in placing a number of men upon each other's shoulders, so that each row consists of a man fewer till they form a pyramid terminating in a single person, upon whose head a boy is sometimes placed with his feet upwards.

MISCELLANEOUS

CURIOUS TRICKS AND FANCIES.

"Youth loves and lives on change,
Till the soul sighs for sameness, which at last
Becomes variety, and takes its place."

AN ARTIFICIAL MEMORY.

The reader must have observed, that to perform several of the recreations in this book, it is necessary to have a good memory; but as that is a gift every one has not from nature, many methods have been contrived to supply that defect by art--the most material of which we shall here describe.

An artificial memory respects either figures or words; for the former, let the five vowels, a, e, i, o, u, represent the first five digits; the diphthongs that begin with the first four vowels, as au, ea, ie, ou, representing the remaining four digits, let y stand for an 0, or cypher. Let the ten first consonants also stand for the nine digits and the cypher, as in the following table:

+----+----+----+----+----+----+----+----+----+----+
| a | e | i | o | u | au | ea | ie | ou | y |
| | | | | | | | | | |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 |
| | | | | | | | | | |
| b | c | d | f | g | h | k | l | m | n |
+----+----+----+----+----+----+----+----+----+----+

Then to represent any number, let the first letter be a vowel or diphthong, the second a consonant, the third a vowel, the fourth a consonant, &c. Thus for the number 1763, you write or remember the word _akaud_; if there are several sums to be retained, you place the words in form of verses--which will make them more pleasing to repeat and more easy to remember; for example, if you would remember the dates of the discovery of America by Columbus, the settlement of Virginia by Captain Smith, the landing of the Pilgrims at Plymouth, the Battle of Bunker Hill, the Declaration of Independence, and the Battle of New Orleans, which were in 1492, 1605, 1620, 1775, 1776, and 1815, you write as follows--for you are to observe that in this, as well as similar cases, when the first figure is always the same, it is unnecessary to write it after the first time:

Afouc hyh hen keag keah lag.

When several cyphers come together, instead of repeating y or _n_, you may write y or _n_ 2, 3, &c.; thus, for 3400, write _ify_2, and for 256,000, write _ehun_3.

To remember any number of words, select the initial letters of those words, and to the first add a, if it begins with a consonant, or b, if it begins with a vowel. In like manner e or c to the second initial letter; to the third add i or d; to the fourth o or f; to the fifth u or g, so that of the five initials you make five syllables, which are joined together in one word--then of the next five initials you make, in the same manner, another word, and of every two words you make a verse; for example, suppose you would remember the names of all the kings of England since the Norman conquest in the order in which they reigned, you then write as follows:

W_a_ w_e_ h_i_ s_o_ h_u_ R_a_ j_e_ h_i_ e_f_ e_g_
E_b_ r_e_ h_i_ h_o_ h_u_ E_b_ e_c_ r_i_ h_o_ h_u_
E_b_ m_e_ e_d_ j_o_ c_u_ C_a_ j_e_ w_i_ a_f_ g_u_ G_a_ g_e_
g_i_ g_o_ w_u_ V_a_.

Or, if you would remember the letters that begin any number of verses, suppose the twenty first lines of Pope's Essay on Man, you write as follows:

A_b_t_e_l_i_t_o_e_g_ A_b_a_c_o_d_t_o_t_u_
T_a_o_c_e_d_a_f_l_u_ B_a_s_e_w_i_o_f_f_u_.

THE MAGICIAN'S MIRROR.

Construct a box of wood, of a cubical shape, A B C D, of about fifteen inches every way. Let it be fixed to the pedestal P, at the usual height of a man's head. In each side of this box let there be an opening, of an oval form, ten inches high, and seven wide. In this box place two mirrors, A D, with their backs against each other. Let them cross the box in a diagonal line, and in a vertical position. Decorate the openings in the side of this box with four oval frames and transparent glasses, and cover each with a curtain so contrived as all to draw up together.

Place four persons in front of the four sides, and at equal distances from the box, and then draw them up that they may see themselves in the mirrors, when each of them, instead of his own figure, will see that of the person next to him, but who will appear to him to be placed on the opposite side. Their confusion will be the greater, as it will be very difficult, if not impossible, for them to discover the mirrors concealed in the box. The reason of this phenomenon is evident; for though the rays of light may be turned aside by a mirror, yet they always _appear_ to proceed in right lines.

THE PERSPECTIVE MIRROR.

Provide a box, A B C D, of about two feet long, fifteen inches wide, and 12 inches high. At the end A C, place the concave mirror, the focus of whose parallel rays is eighteen inches from the reflecting surface. At I L place a pasteboard, blacked, in which a hole is cut, sufficiently large to see on the mirror H the object placed at B E F D. Cover the top of the box, from A to I, close, that the mirror H may be entirely darkened. The other part, I B, must be covered with glass, under which is placed a gauze or oiled paper, to prevent the inside from being seen. Make an aperture at G, near the top of the side E B, beneath which, on the inside, place in succession, paintings of vistas, landscapes, figures, &c. so that they may be in front of the mirror H. Let the box be placed that the object may be strongly illuminated by the sun, or by wax-lights placed under the inclosed part of the box A I. By this simple construction, the objects placed at G D will be thrown into their natural perspective, and if the subjects be properly chosen and well executed, the appearance will be both wonderful and pleasing.

THE MAGICAL GYROSCOPE.

A little instrument has been constructed lately, exhibiting such remarkable results in connection with rotary motion, that it has greatly puzzled most of those who have witnessed its strange performances. Although many of our readers may have seen the instrument, yet from the numberless inquiries that have been made for the rationale of its peculiar feats, and also from the fact that we have not yet heard a solution that appears to be the true one, we are induced to furnish a brief description and explanation of the whole.

It consists of a brass wheel, B, four or five inches in diameter, with a thick lead rim, or circumference, so as to impart to the wheel when revolving rapidly sufficient momentum to cause it to spin for some minutes. The axis of this wheel terminates in pivots, set in a circular ring at right angles to the wheel, as the figure represents. Two small flat pieces of brass (A and C) are soldered outside to opposite sides of this ring, and a small cavity is made on the under side of each piece, so that the whole may rest on a pointed upright wire, placed in one of these cavities, this wire being inserted in a heavy metallic base to give it solidity. A small hole is made in the axis of the wheel, so that the end of a cord may be thrust through, the cord wound around it, and rapid motion imparted to the wheel like the spinning of a top. This constitutes the whole of the apparatus, which is shown in Fig. 1.

Now, by placing the wheel and its ring, on the upper end of the pointed wire, as shown in the figure, _only one side being supported_, the wheel and ring would of course, immediately fall by the force of gravity, there being no support at the other side, C. But if a rapid spinning motion is given to the wheel by means of the cord already described, and it be placed on the point at A, _it will not fall_, but will move slowly around on the upright point, performing a steady, revolving horizontal motion, as long as the rapid rotary motion of the wheel continues. So steady and uniform is this horizontal movement, that it generally suggests the motion of the planets round the sun.

This _self-upholding_ property constitutes the wonder and puzzle of the instrument, and many explanations have been attempted. Some ascribe it to atmospheric influence; others to electricity; while others confidently remark, "Ah, yes, I understand it--it is the _motion_ which keeps it from falling--it is the momentum--the centrifugal force;" but _why_ this result is produced by centrifugal force, we are not told.

The true explanation is this:

1. The wheel when at rest, may of course be easily moved about so as to alter the position of its axis, in any direction. But this is not so when it is made to spin rapidly; if the ring is held in the hands, the wheel will be found strongly to resist any side or twisting movement--so much so, that a novice will start, and almost let it drop, supposing there is something _alive_ in it or, as they sometimes remark; "Why! it feels as if there was a _snake_ in the wheel!" This is owing to nothing but the strong momentum of the _lead rim_ (already described) tending to keep the wheel in its position; for an attempt to alter its position, throws all this swiftly flying matter into a different course, which, it is evident, cannot easily be done.

2. The _slowly revolving_, horizontal motion on the pivot at A is in a contrary direction to the _spinning_ motion of the _top_ of the wheel, as the arrows show in Fig. 1. In other words, the forward portion of the wheel flies upwards, and the back portion downwards. This will be found to be always the case.

3. Now, when the wheel is moving on horizontally around the pivot at _a_, the forward portion of the rim is continually moving to the _left_, and the hinder portion to the right, as represented in Fig. 2. The combined motion of the forward part of the wheel both upward and to the left, is therefore not perpendicularly upward, but inclined to the left, and the tendency of its momentum is to throw the top of the wheel also to the left. In the same way, the downward momentum behind throws the bottom to the right. Throwing the top to the left and the bottom to the right, of course raises the wheel as it rests on the pivot A. In other words, the combined motion of the wheel on its axis, and on the pivot A, constantly tends to raise it, thus overcoming gravity, and maintaining the wheel in its position, supported only at one end.

4. The momentum of the lead rim, as described in (1.) tending to keep the wheel in its position, keeps it also in a uniformly horizontal attitude; if placed by the hand, inclining upwards, it will move around on the pivot at _a_, without altering this inclination; or the same result takes place, if inclined below the horizontal.

5. The reason of the forward horizontal movement, is this: the spinning force of the wheel tends to throw it to the left, and consequently to lift it upwards, as shown in (3.)--gravity, on the opposite hand, tends to draw it downward; the _resultant_ (or mid-way) motion is therefore between them, or horzontally. As a proof that gravity thus produces the onward movement--when the wheel spins with the greatest rapidity, and consequently has the greatest relative force to gravity, the horizontal movement is slowest; but it continues constantly to increase as the motion of the wheel is retarded, and as gravity assumes a greater proportionate force.

THE ARTIFICIAL LANDSCAPE.

Procure a box, as in cut, of about a foot long, eight inches wide, and six inches high, or any other dimensions you please, so they do not greatly vary from these proportions. At each of its opposite ends, on the inside of this box, place a piece of looking-glass, that shall exactly fit; but at that end where the sight hole A is, scrape the quicksilver off the glass, through which the eye can view the objects.

Cover the box with gauze, over which place a piece of transparent glass, which is to be well fastened in. Let there be two grooves at each of the places C D E F, to receive two printed scenes, as follow: On two pieces of pasteboard, let there be skillfully painted, on both sides, any subject you think proper, as woods, bowers, gardens, houses, &c.; and on two other boards, the same subject on one side only, and cut out all the white parts: observe also, that there ought to be in one of them some object relative to the subject, placed at A, that the mirror placed at B may not reflect the hole on the opposite side.

The boards painted on both sides are to slide in the grooves C D E F, and those painted on one side are to be placed against the opposite mirrors A and B; then cover the box with its transparent top. This box should be placed in a strong light, to have a good effect.

When it is viewed through the sight hole, it will present an unlimited prospect of rural scenery, gradually losing itself in obscurity; and be found well worth the pains bestowed on its construction.

EASY AND CURIOUS METHODS OF FORETELLING RAINY OR FINE WEATHER.

If a line be made of good whipcord, that is well dried, and a plummet affixed to the end of it, and then hung against a wainscot, and a line drawn under it, exactly where the plummet reaches, in very moderate weather it will be found to rise above it before rain, and to sink below when the weather is likely to become fair. But the best instrument of all, is a good pair of scales, in one of which let there be a brass weight of a pound, and in the other a pound of salt, or of saltpeter, well dried; a stand being placed under the scale so as to hinder it falling to low. When it is inclined to rain, the salt will swell, and sink the scale: when the weather is growing fair, the brass weight will regain its ascendancy.

Another very simple method is, to take a strip of pine wood, about twenty inches long, one wide, and a quarter thick, and cut across the grain. Then take a strip of cedar, of the same dimensions, but cut along the grain. Glue them firmly face to face, and set them upright in a stand. Some time before rain falls, the pores of the pine will absorb moisture from the atmosphere, and swell until the whole forms a bow, which will straighten itself as fine weather approaches. It is needless to say that the rods should not be painted or varnished.

THE MAGICAL MEASURE.

The line to be measured must not be extravagantly long, otherwise it will be difficult to measure it accurately; for the least failure of a just aim, or departure from an upright position, would make very sensible errors in the measure of a very long line, especially if the ground was very uneven. To measure then the line A B, accessible at the extremity A, suppose the breadth of a small river, he who pretends to measure must stand very straight at the extremity A, and support his chin with a little stick resting upon one of the buttons of his coat, so as to keep his head steady in one position. He must pull his hat down upon his forehead till the brim of his hat covers from his view the inaccessible extremity B of the line to be measured A B, then he must turn himself to a level, uniform piece of ground, and with the same position of his hat, observe the point of the ground where his view terminates, as C, then measuring with a line or chain the distance A C, he has the length of the line proposed A B.

THE BOUNDLESS PROSPECT.

Take a square box, about six inches long and twelve high, or of any other proportionate dimensions. Cover the inside with four flat pieces of looking glass placed perpendicular to the bottom of the box. Place at the bottom any objects you please, as a piece of fortification, a castle, tents, soldiers, &c. On the top, place a frame of glass shaped like the bottom of a pyramid, as in the figure, and so formed as to fit on the box like a cover. The four sides of this cover are to be composed of ground glass, or covered inside with gauze, so that the light may enter, and yet the inside be invisible, except at the top, which must be covered with transparent glass: when you look through this glass, the inside will present a pleasing prospect of a boundless extent; and, if managed with care, will afford a deal of amusement.

THE HOUR OF THE DAY OR NIGHT TOLD BY A SUSPENDED SHILLING.

However improbable the following experiment may appear, it has been proved by repeated trials:

Sling a shilling or sixpence at the end of a piece of thread by means of a loop. Then resting your elbow on a table, hold the other end of the thread betwixt your fore finger and thumb, observing to let it pass across the ball of the thumb, and thus suspend the shilling into an empty goblet. Observe, your hand must be perfectly steady; and if you find it difficult to keep it in an immovable posture, it is useless to attempt the experiment. Premising, however, that the shilling is properly suspended, you will observe, that when it has recovered its equilibrium, it will for a moment be stationary: it will then of its own accord, and without the least agency from the person holding it, assume the action of a pendulum, vibrating from side to side of the glass, and, after a few seconds, will strike the hour nearest to the time of day; for instance, if the time be twenty-five minutes past six, it will strike six; if thirty-five minutes past six, it will strike seven; and so on of any other hour.

It is necessary to observe, that the thread should lie over the pulse of the thumb, and this may in some measure account for the _vibration_ of the shilling; but to what cause its striking the precise hour is to be traced, remains unexplained; for it is no less astonishing than true, that when it has struck the proper number, its vibration ceases, it acquires a kind of rotary motion, and at last becomes stationary, as before.

CONTRIVANCE FOR A WATCH LAMP, PERFECTLY SAFE, WHICH WILL SHOW THE
HOUR OF THE NIGHT, WITHOUT ANY TROUBLE, TO A PERSON LYING IN BED.

It consists of a stand, with three claws, the pillar of which is made hollow, for the purpose of receiving a water candlestick of an inch diameter. On the top of the pillar, by means of two hinges and a bolt, is fixed on a small proportionate table, a box of six sides, lined with brass, tin, or any shining metal, nine inches deep, and six inches in diameter. In the center of one of these sides is fixed a lens, double convex, of at least three inches and a half diameter. The center of the side directly opposite to the lens is perforated so as to receive the dial-plate of the watch, the body of which is confined on the outside, by means of a hollow slide. When the box is lighted by a common watch-light, the figures are magnified nearly to the size of those of an ordinary clock.

THE ENCHANTED PALACE.

On the six-sided plane A B C D E F of the figure, draw six semi-diameters; and on each of these place perpendicularly two plane mirrors, which must join exactly at the center, and which, placed back to back, must be thin as possible. Decorate the exterior boundary of this piece, (which is at the extremity of the angles of the hexagon,) with six columns, that at the same time serve to support the mirrors by grooves formed on their inner sides. Add to these columns their entablatures, and cover the edifice in whatever manner you please. In each one of these six triangular spaces, contained between two mirrors, place little figures of pasteboard, in relief, representing such subjects, as when seen in an hexagonal form, will produce an agreeable effect. To these add small figures of enamel, and take particular care to conceal by some object that has no relation to the subject, the place where the mirrors join, which, as before observed, all meet in the common center.