scription, six penny stamps, which we have sent to the Rev. Mr. Curwen, of Plaistow, in Essex, who wrote the appeal on the lady's behalf, and who alone is in communication with her, is a sufficient proof that the letter and the transaction which it so simply, yet beautifully, describes, are real and not fictitious.] according to the cases with which they are construed. Some of them are construed with the genitive only; some with the dative only; some with the accusative only; and some either with the dative or accusative, according to circumstances. (2) They may also, on a different principle, be divided into two general classes: the Primitive and the Derivative. The primitive prepositions always govern either the dative or the accusative: the derivative prepositions are found, for the most part, in connection with the genitive only. CORRESPONDENCE. INDUSTRY AND CHARITY. ANSWERS TO CORRESPONDENTS. UN INGENIERO CIVIL: Try Nesbitt's Land Surveying or old Croker.ELITERA should apply to the minister or curate of his parish. T. H. (Workington) must apply at the Herald's office; we can't assist him.-A TYPO (Darlington): Yes.-ELEMENTARY (Newcastle) must look more narrowly at our later numbers. OLD SUBSCRIBER (Limehouse) will find it necessary to buy blank books for bookkeeping, cheap, as he says, and rule them himself. UN ETUDIANT FRANÇAIS (Guernsey): The sections referred to in the French were omitted as useless.-E. WHEREAT (Bristol) and J. E. S. A.: This poor widow hath cast more in, than all they who have cast into the Their kind suggestions will be kept in view.-R. M. H.: Vols. i., il., and treasury."-Mark xii. 43. iii. of the P. E. are bound separately, and the cheapest may be had for 3s. 6d. each. SIR,-This evening we received our weekly allowance of mental food in the shape of the POPULAR EDUCATOR, with one or two minor publications, which we use as sauce for goose and gander; or, rather, to amuse us in the evenings, after the study of the English, Latin, and other lessons, that the P. E. provides for us. Well, sir, I have said that we obtained your paper this evening, and, as is generally the case, whilst my wife is busily engaged in clearing the tea-things from the table, I take the EDUCATOR and look down the outside columns of it, so as not to lose one morsel of the knowledge which is often elicited from you by some questioning correspondent who has been kind enough to ask for the very thing I wanted. I have learnt some good precepts, some useful hints, in this manner, without (in my way of thinking) losing time. You must know, sir, that my boys attend the day-school in our village, where, amongst other things, English grammar and composition are taught. These are favourite studies with my boys; so that you will suppose I (who never knew English grammar before I studied the P. E.) am obliged to make the most of my time to keep pace with them; for I like not the idea of my boys learning that of which I (their father) know nothing. On scanning the column of Correspondence, I saw your kind-hearted appeal to us, in behalf of an unfortunate lady who is behind-hand with the P.E. I immediately proposed the following question:-" Who will vote for the selling of the P. E. for the purpose of getting some plum-cake at Christmas?" Not a voice! "Which is the better for us, to have plum-cake or the POPULAR EDUCATOR?" “EDUCATOR,” cried three voices at once. Well, then, said I, a poor lady is in want of some help, so that she may be enabled to purchase the remaining numbers which she has not in her possession. I then proposed this resolution: that we make a subscription of one penny each, to send to the editor, for the benefit of this poor lady. The boys went each one for his saving-box; I think, sir, you would have smiled to see their alacrity; the penny each was placed on the table, my penny with theirs. My wife gently hinted the impracticability of sending pence, and proposed the making up of the sum to sixpence, which could go in a note; for, said she, though we have enough to do to make both ends meet, we are not unwilling to give to a good cause. She is willing, I assure you. I heard her say, not long since, she would make a half-pound of sugar serve us for a week, rather than that her husband should go without the P. E. We hope the unfortunate, but well-deserving object of your appeal will succeed in her praiseworthy exertions; and by some means be placed above the necessity of studying at such a disadvantage. She will surely thank you for your kind-hearted hint, which we hope will be met by as kind a sympathy by very many of our fellow-Christians. We would that ours was a larger sum; but, sir, we give a little and wait. If we hear from you again-as my boys are saving their money for an Easter holiday-we will raise another subscription. I beg you to look down from your learned eminence, and spare, or gently point out, the errors of your pupil, who is A DAILY LABOURER. P.S.-My boys are longing to see the letter which, say they, father is writing to the editor of the POPULAR EDUCATOR. December 7th, 1853. H. GUY (Moorsley): His "Remarks on the Study of Grammar” are very well written. Let him persevere, and he will greatly improve.-J. P. (Shepwyke): We should be very glad to oblige him, but the lines he wishes to be inserted are an advertisement.-J. HALL (Hyde): See Errata, p. 164. "When two volumes of pure hydrogen gas are mixed with one volume of pure oxygen gas, and the mixture inflamed in a proper apparatus by the electric spark, the gases totally disappear, and the interior of the vessel is covered with drops of pure water, equal in weight to that of the gases consumed."-Brande's Chemistry. 5. CLARE (Ashton-under-Lyne): His remarks on the asymptotic paradox are very excellent, and we would insert them if we had room.-W. WARD not well put.-NAVIGO (Newton) will be answered.-D. JARVIS (Glasgow) : (Stepney) and W. B. HODSON (Lincoln): The questions are very old, and Received.-R. T. S. O. (Bromley) should study English before Bookkeeping. E. T. B. P. (Liverpool): We have made no errors in the Map of France; for we consider the Chief Towns as those which have the largest population, and not those which are appointed so by any government whatever! !-OLD BOB (Queenshead) is too technical for us. JOHN CUNNINGHAM (Liverpool): In our lesson on the impressions of rain-drops on the surface of sandstone, we ascribed the discovery of these phenomena to Dr. Buckland. Mr. Cunningham has shown to us that it was he who first observed these impressions, and that it was he who first called Dr. Buckland's attention to them. He does us the justice to say that we robbed him of this honour" unintentionally." We are, therefore, happy in having this opportunity of correcting our error, and of giving to him the palm which he has so well deserved. together, one hour an evening, and you will get on.-J. ROBINS should study ENRICE L. FILLIPE (Stamford-street): Study Italian and English Our lessons in Penmanship and English Grammar, and his difficulties will disappear. L. FERNANDEZ (Oldham) wants to know our opinion of an exceedingly bad sentence in English, and whether there be any treatises on woollen cloth and on ventriloquism!!-J. B. (Manchester): You are learning the very system that the American minister recommends, viz., Ollendorf's. JAMES RUSSELL (44, Meadowside, Dundee) very kindly offers to give assistance gratis to the students of the POPULAR EDUCATOR who reside in his neighbourhood, in Cassell's Arithmetic, Algebra, and Euclid, between the hours of 5 and 7 P.M., or 9 and 10 P.M. We feel assured that many of our readers in Dundee will most gladly avail themselves of this generous offer. MRS. SLIPSLOP (Aberfeldy): We thank her for the loan of her spectacles, they are better than ours; whether the printer's pair or ours were in fault, it is now too late to determine; but we are glad to make the necessary Correction. The error has arisen thus: there are two Nahors in Genesis correction. The error has arisen thus: there are two Nahors in Genesis xi., viz., one in v. 22 and 23, and another in v. 26, 27, and 29; the one was the father of Terah, and the other his son; the former has been, by some unaccountable mistake, omitted in our table, p. 3, vol. i. E. BYRT (Shepton Mallet): Yes.-ROBERT HUMBLE (Hartlepool): The laws of the resistance of the air to falling bodies will hereafter be considered. The rule for finding the height of a tower, as usually given, is, of course, not strictly correct. G. ASPINALL (Liverpool): Apply to Mr. Bell, 13, South Charlotte-street, Charlotte-square, Edinburgh. THE PENCIL (Paddington): We are just thinking of the students of the pencil, and mean to do something soon.J. R. M. (Glasgow): See col. 1, p. 376, vol. iii.-AMATOR SCIENTIA (Dundee): We prefer Bell's system to Pitman's.-H. HALES (Southwark): We doubt much whether he would succeed in the business of making cheap apparatus and selling it himself. He had better apply to our friend Mr. J. Griffin, of Finsbury-square, and see what can be done there. ISAAC NEWTON (Sheffield): Our friend with this glorious nom de guerre has not so sustained the credit of the name as to admit of the insertion of his solution of the boy and apple question!!-W. E. WILLIAMS (Pentrebach): The lessons in English are closed for the present; as soon as possible Elocution will be taken up.-G. S. (Cupar): We know of no such book as a treatise on Greek pronunciation.-W. WALLIS (St. Ninian's): Mr. Bell did not say that his "Vocabulary of Syllabic Logograms" was to be inserted in the P. E.; you have, therefore, no right to expect them in our pages. Several correspondents have committed this error. [We hope that our readers will be as much pleased with this letter as we have been. It does much credit both to the head and the heart of the writer, as well as to those of his amiable family. We can assure the most critical of our readers that it is a genuine production, and not got up for the sake of puffing the P. E.-a thing of which we have been most unjustly accused. We have not the most remote idea of the author or of his locality; but the sub-bility. ERRATUM. Fol. iv., p. 155, col. 1, line 10 from bottom, for insolubility read ON PHYSICS OR NATURAL PHILOSOPHY. No. XVII. (Continued from page 235.) PNEUMATICS. GASES AND THE ATMOSPHERE. Physical Nature of Gases.—Gases or aeriform fluids are bodies whose particles possess perfect mobility, and which are in a constant state of repulsion called expansibility, tension, or elastic force; in conformity with the latter of these appellations, gases are frequently denominated elastic fluids. The elastic fluids are divided into two classes, 1st, the permanent gases, or those which are properly called gases; and 2nd, non-permanent gases, or vapours. The former are those which maintain their aeriform state under any pressure or diminution of temperature, as oxygen, hydrogen, nitrogen, binoxide of nitrogen or nitric oxide, and carbonic oxide. The non-permanent gases, on the contrary, easily pass into the liquid state, either by strong pressure or by lowering the temperature. This distinction, however, is not rigorously correct, for a great number of gases, which were considered permanent, have been liquefied by Faraday and others, and it must be admitted that those which have not hitherto been liquefied, would be so if they were subjected to sufficient pressure, or lowering of temperature. Gas, therefore, is the name applied to bodies which, under ordinary pressures and temperatures, exist only in the aeriform state; whilst vapour is the term applied to the aeriform state which bodies take under the application of heat, bodies which, like water, alcohol and ether, exist in a liquid state under ordinary pressures and temperatures. In chemistry, the gases at present known are 14 in number, of which 4 are simple, viz. oxygen, hydrogen, nitrogen, and chlorine; 7 are found in natural productions, viz. oxygen, nitrogen, carbonic acid, protocarburetted hydrogen (marsh gas) and bicarburetted hydrogen (olefiant gas), ammonia and sulphurous acid. All the other gases are only obtained by chemical processes. Expansive Force of Gases.-The expansive force of gases, that is, their tendency always to assume a greater volume, is proved by the following experiment. Place under the receiver of an air-pump a moistened bladder furnished with a stop-cock, and containing a quantity of air. At first, there is an equilibrium between the elastic force of the air in the receiver and that of the air enclosed in the bladder; but as soon as the exhaustion of the receiver commences, the pressure on the bladder is diminished, and it swells or expands, as the process of exhaustion advances, just as if it were inflated by the addition of a greater quantity of air; this expansion proves that the air which it contains possesses an elastic force; see fig. 62. Fig. 62. When the exterior air is re-admitted into the receiver by ineans of the proper stop-cock, the bladder is again compressed by it, that is, reduced to its former dimensions, the equilibrium being restored. In the same manner, we may easily prove the fact of the expansive force of all the gases. In consequence of its expansive force, it seems as if any gas contained in an open vessel would make its instantaneous escape. Such indeed is the case, if the vessel be placed in a vacuum; but, in ordinary circumstances, the pressure of the exterior air is opposed to the issue of a gas from the vessel. It can be proved indeed, by experiment, that an equilibrium can be made with the expansive force of any gas, only by the counteracting pressure of a gas of the same nature as itself. the expansive force of hydrogen or carbonic acid. These gases, Thus, the pressure of the air cannot make an equilibrium with however, do not escape into the air from the vessels containing them, as they would in a vacuum; but the interior and exterior fluids are rapidly mixed together, as we shall see in the sequel. It will then be shown that the elastic force of gases is always equal and contrary to the pressure which they support, and that it increases with their temperature. Process of collecting Gases.-A great many gases being colourless, inodorous and insipid, do not fall immediately under the cognisance of the senses, like solids and liquids; but they become apparent by the processes employed in collecting them. Suppose, for example, that it was required to get hydrogen, a gas which forms one of the elements of water.* We take a double mouthed bottle в, fig. 63, furnished with two tubes, and introFig. 63. * Water is composed of two gases, oxygen and hydrogen. 95 1 By the mutual action of the zinc and the sulphuric acid, the water in the bottle is decomposed; its oxygen is united with the zinc, and the sulphate of zinc is produced, which remains in solution; its hydrogen is now set at liberty, and passes, in consequence of its elastic force, into the bell-shaped glass A, where it rises to the top on account of its lightness, or its having less specific gravity than water. The other gases are collected in a similar manner, but under the influence of very different chemical reactions. Transference of Gases from one Vessel to another.-In the same way as liquids are treated, so gases can be poured from one vessel into another. This experiment is easily made with carbonic acid, which is much denser than common air. Thus, we fill a bell-shaped glass with this gas, by collecting it in the manner above mentioned; then, taking a second vessel of the same kind and size and full of air, we pour the contents of the former into the latter, as shown in fig. 64, holding them for some time in a fixed position. In consequence of its excess of density, the carbonic acid descends slowly from the vessel m into the vessel n, from which it drives out the air, so that as soon as the vessel n is full of carbonic acid, the vessel m is full of air. The proof of this rests on the property which carbonic acid possesses of extinguishing lighted bodies. For, before the experiment, a lighted taper burns in the vessel and is extinguished in the vessel m; whilst after the experiment the contrary is the case. points, and acts with equal force in all directions. As to the pressure arising from the action of gravity, it is regulated exactly according to the laws of the pressure of liquids formerly explained; that is, that it increases proportionally to the density and to the depth; that it is constant on the same horizontal stratum; and that it is independent of the form which the gaseous mass assumes. Moreover, for volumes of gas of small dimensions, this pressure is so little that the consideration of its amount may be, in ordinary cases, entirely omitted. THE ATMOSPHERE. Composition of the Atmosphere.-The name atmosphere is applied to that great ocean of air which surrounds our globe, and is carried along with it, in its daily and annual revolutions. The air was considered by the ancients as one of the four elements of which all things consisted. Modern chemistry has shown that it is a mixture of nitrogen and oxygen, containing in 100 cubic inches of the mixture, 79-20 cubic inches of nitrogen and 20-80 cubic inches of oxygen. Moreover, in 100 ounces of air, there are 76.99 ounces of nitrogen and 23'01 ounces of oxygen. The atmosphere also contains a quantity of the vapour of water which varies with the temperature of the air, the seasons, the climates, and the direction of the winds. Lastly, the air contains of carbonic acid in a given volume, at a mean, only about a two-thousandth part. The carbonic acid is produced by the Weight of Gases. From their extreme fluidity, and especially respiration of animals, and the combustion and decomposition of their expansibility, gases would seem not to be subject to the organic substances. According to the estimate of M. Bouslaws of gravity; but these subtle fluids obey this force as singault, there are nearly three millions of cubic metres (about well as solids and liquids. In order to prove this, suspend 660 millions of Imperial gallons) of carbonic acid produced at under the scale of a very sensible balance, a glass globe capable Paris, by these processes, in twenty-four hours; the part proof holding about a gallon of air, and furnished with an air-duced by animal respiration being about one-ninth of the whole. tight stop-cock, see fig. 65. First weigh this globe full of air; Fig. 65. Notwithstanding the continual production of carbonic acid at the surface of the globe, the composition of the atmosphere does not appear to be altered by it: the reason is, that in the process of vegetation, the green parts of the vegetables decompose the carbonic acid under the influence of the solar light, assimilating the carbon and giving back to the atmosphere the oxygen which is continually abstracted from it by the respiration of animals and by combustion. Air being heavy, if we conceive the atmosphere to be divided into horizontal strata, it is plain that the superiorstrata will press on those below them, by their weight, and the result will be the compression and condensation of the inferior strata. As the pressure on any stratum will evidently diminish as the number of superincumbent strata diminishes, the air is evidently rarified in proportion to its distance from the surface of the globe. In consequence of the expansive force of the air, it would seem that the particles of the atmospheric air should extend indefinitely into the planetary spaces. But by the very effect of dilatation, the expansive force of the air decreases more and then, after having created a vacuum in it by means of the air-more; moreover, it is lessened by the low temperature of the pump, weigh it again, and it will be found that the weight of st the second time will be some grains * less than it was the first time, showing that this weight of air has been withdrawn from the glass globe. By the preceding process, it has been found that 61 cubic inches of pure air at the temperature of 32° Fahrenheit, and under an atmospheric pressure of 30 inches in the barometer, weighs 20 grains, the same quantity of hydrogen weighs 1.39 grains, or about 14 times less than air; and the same quantity of hydriodic gas, which is the densest of the gases, weighs 89 grains. The Pressure of Gases.-Gases produce two kinds of pressure, one on the particles of which they are composed, and another on the sides of the vessels which contain them; the one proceeds from their elastic force, and the other from their weight. The pressure which arises from their elastic force is transmitted with the same intensity to all points of the mass of the fluid and the sides of the containing vessel; for the repulsive force which exists between the particles is the same at all * About 90 grains, if the temperature of the air be taken at that of the maximum density of water, and the exhaustion be complete. higher regions of the atmosphere, so that there is a point where an equilibrium is established between the expansive force of the particles of the air, and the action of gravity which attracts them to the centre of the earth; hence it is concluded that there is a limit to the extent of the atmosphere. From the weight of the atmosphere, its decrease in density, and the observation of crepuscular (twilight) phenomena, its altitude is estimated at about 40 miles from the surface; beyond this limit, the air is extremely rarified; and beyond the altitude of about 50 miles, it is considered that there is an absolute vacuum. Since we have already stated that the air is a heavy body, and given the actual weight of a certain quantity near the surface, it is evident that the whole of the atmosphere must act upon the surface with a very considerable pressure. The actual existence of this pressure is proved by the following experiments. The Bladder Glass-Take a short glass cylinder about 4 inches in diameter, ground smooth at one end, and furnished with a bottle-lip at the other; over this end fasten a piece of bladder, so as to be perfectly air-tight; well grease the ground end of the cylinder, and place it firmly on the receiver plate of an air-pump, so that no air may be admissible at the If, instead of the piece of bladder fastened to the top of the cylinder, there be placed on it a square piece of thin glass made air-tight, by having this end of the cylinder also ground smooth and well greased, you will find that on the application of the air-pump to exhaust the cylinder, the glass will first bend under the pressure of the external atmosphere, and then break into pieces with a loud crash. Magdeburg Hemispheres.-The bladder-glass appears only to prove the existence of the atmospheric pressure vertically downwards. By means of the Magdeburg hemispheres so (named from the town where they were first invented), it is proved that this pressure acts in all directions. This apparatus is composed of two hollow brass hemispheres, between 4 and 5 inches in diameter, fig. 67, furnished with broad edges ground Fig. 67. atmosphere presses the hemispheres together; for it will take a force of about 500 lbs. to separate them, supposing their diameter to be 5 inches, and that the exhaustion of the air were complete. This may be proved by fastening the one handle to a beam, suspending a scale to the other handle, and loading it with weights until the hemispheres be separated. In the original experiment performed by Otto Von Guericke at Madeburg, in 1560, there were from 14 to 30 horses harnessed to the hemispheres, which were two feet in diameter, without effecting a separation; when more horses were added, the hemispheres parted with a loud report. If after the attempt to separate the hemispheres by a force less than sufficient to separate them, the stop-cock be turned so as to re-admit the air into the apparatus, they can then be separated with the external and the internal air has been restored. greatest ease, because the equilibrium of pressure between the MEASURE OF ATMOSPHERIC PRESSURE. The Torricellian Experiment.-The preceding experiments prove the existence of atmospheric pressure, but do not acquaint us with its amount. The following experiment made for the first time in 1643, by Torricelli, a disciple of Galileo, of its pressure on every square inch of surface at the bottom of a gives the exact measure of the weight of the atmosphere, or column of this size, extending to to the top of the atmosphere. Take a glass tube CD, fig. 69, not less than 33 or 34 inches smooth and made to fit each other exactly, so that when well greased they are completely air-tight. These hemispheres are each fitted with a strong ring or handle, and one of them is furnished with a tube which may be screwed on the plate of the air-pump, and a stop-cock to prevent the re-admission of the air. In making the experiment, first place the hemispheres together with their edges well greased, and in close contact; screw the apparatus to the plate of the air-pump, exhaust the air from the sphere as completely as possible, turn the stop-long, closed at one end, open at the other, and of any convecock to exclude the air, and unscrew the apparatus from the nient diameter from of an inch to an inch. Having placed C this tube in the vertical position with the closed end downwards, fill it completely with mercury; then, closing the open end c with the finger or thumb, invert the tube and immerse this end in a cup nearly full of mercury. Withdrawing then the finger from the tube at B, and supporting it with the other hand at A, the column of mercury in the tube will sink two or three inches, and then become stationary at a height AB of about 30 inches above the mercury in the cup, when the experiment is performed at the level of the sea, and during a mean state of the atmosphere. In order to explain the nature of this experiment, we observe, that as the pressure of the atmosphere acts with great regularity on the superficial stratum of liquids placed in an open vessel, it does not in general disturb the horizontality of such surfaces. But if by any means a limited portion of this stratum be protected from the atmospheric pressure, the equilibrium will be destroyed, and the liquid will rise up to fill the vacuum produced above it, to a determinate height depending on the nature of the liquid. This is indeed what takes place when we immerse the one extremity of a tube in water, and withdraw the air by suction at the other extremity. By this process, we only diminish the pressure within the tube; but in the Torricellian experiment the pressure of the air is completely removed, and there is a complete vacuum at the top of it when inverted. We have seen, that on the moment of the inverted end becoming free, the mercury in the tube descends to a level about 30 inches above that of the mercury in the open cup; this level is always the same whatever be the length of the tube, its shape, or its inclination. In this experiment the elevated column in the interior of the tube presses on the part of the cup on which it stands, with a force which replaces that of the atmosphere; but the latter still continues to press with the same force on the rest of the surface of the mercury in the cup; and the particles of the liquid, yielding to this pressure, would have been forced up the tube to the same height, supposing that it had been a perfect vacuum, on its immersion. In fig. 70, where a section of the tube and Fig. 70. are inversely proportional to their densities. On the other hand, if the weight of the atmosphere increases or diminishes from any natural cause, in any given place, it is evident that the length of the mercurial column will increase or decrease accordingly. Pascal's Experiments.-The celebrated Pascal, wishing soon after, to prove for himself that the force which supported the mercury in the tube of Torricelli was really the pressure of the atmosphere, had recourse to the two following experiments, which placed the fact beyond a doubt. First, foreseeing that the column of mercury ought to descend in the tube in proportion as it was raised in the atmosphere, because that then its pressure would be diminished, he requested a relation living in the province of Auvergne, in France, to repeat, on the mountain called Puy-de-Dome (4,846 feet high) the experiment of Torricelli. Here the column of mercury was diminished in height by a quantity which was between three and four inches in length; this proved that it was really the weight of the atmosphere which sustained the mercury in the tube; because, as this weight decreased, so did the column of mercury. Secondly, Pascal repeated the experiment of Torricelli, at Rouen, in 1646, with another liquid instead of mercury. He took a tube of about fifty feet long, closed at one end and open at the other; he filled it with water, and inverting it, placed it in a reservoir full of water; he then observed that the water in the tube sunk to the level of about thirty-four feet above the level of the reservoir. Now the altitude of the column of water being about 13.6 times that of the column of mercury, and the density of mercury being about 13.6 times periment is equal to the weight of the column of mercury in that of water, the weight of the column of water in this exthe Torricellian experiment; hence it is justly inferred again, that it is the pressure of the atmosphere which equally supports both of the liquid columns. LESSONS IN GREEK.-No. XX. BY JOHN R. BEARD, D.D. THE NUMERAL ADVERBS DENOTE how many times a number is to be taken, as "six times six make thirty-six ;" here six times is a numeral adverb; thus diç signifies twice, rpus three times. The termination of the numeral adverbs is in general κις (ακις, τακις), which is annexed to a cardinal, as τεσσαρακις, ἑξακις, ἑκατοντακις. MN, M...... .....N 11 ένδεκακις 12 δωδεκακις 13 тpiçkaidɛakkig 100 ἑκατοντακις 200 διακοσιακις 300 τριακοσιακις 14 τετταρεςκαιδεκακις Οι τεσσαρ. 1000 χιλιάκις 15 TEVTEKαidEKAKIS cup is shown, it will be observed, that when the mercurial 2000 διςχιλιάκις 10,000 μυριάκις 20,000 διςμυριακις RECAPITULATORY EXERCISES FROM THE CLASSICS. 1. Αναχαρσις κρειττον ελεγεν, ένα φιλον εχειν πολλου άξιον, If we perform the same experiment with any other liquid instead of mercury, we must have recourse to much longer tubes, in order to produce the vacuum at the top of the column. η πολλους μηδενος αξιους. 2. Αννων, ὁ πρεσβυτερος, εκ της The heights to which different liquids rise, in such experiments, | Λιβυης επέρασε μεγαλην δύναμιν εις Σικελιαν, πεζ, να ενας |