used in Anglo-Saxon edifices, consisting of lar stakes and sharp thorn bushes. Afterwards let the vallum be separated by large spaces, and let the foundation of the wall be joined into the native rock. Let the high walls be supported externally by columns (i. e. buttresses); and let the surface of the wall be made fair with a trowel, and have the smoothness of mason's work. The embrasures of the battlements must be separated by equal distances. The battlements must defend the tower, placed on an elevated spot, nor must there be wanting scaffolding to sustain the stones to be thrown (at the enemy)." We have no perfect castles of the period to which this description belongs, and I think that it contains information which may help to set at rest one or two disputed questions relating to military architecture. In another and much larger work of Neckam's, a kind of encyclopædiac treatise, t the following passage occurs:-"Let the surface of the area be levelled by means of the roller, and let the inequalities of the surface be overcome by frequent blows of the beetle, and then let the solidity of the foundation be tried by stakes driven into the bowels of the earth. The wall next rises up, constructed with mortar and stone, according to the law of part of a cornice to make a termination the level and plummet. And let the exterior (marked a in the engraving). (To be continued.) Notes on Mediæval Architecture and FOR the following we are indebted to a paper read before the last meeting of the British Archæological Society by Mr. Thomas Wright, A.M., one of the secretaries to the institution: of the wall be made smooth and even with the mason's trowel; but it is to be known that no walls, even when constructed of wooden laths, make equi-distant lines. For let it be, that wooden walls be so constructed proportionally that they are not of greater thickness at the bottom than at the top, still the surfaces will not be equi-distant. For it necessarily should be, that the higher the walls rise from the ground, the greater distance be found between them. For since every heavy body naturally tends to a centre, you must understand that the walls tend to the centre of the earth, and together. Do not you see how the rays proyou will find that the walls make an angle ceeding from the axle of a cart are at a greater or less distance from each other until they join the circle of the wheel? So are the walls raised up towards the convex of heaven. A ceiling is placed on them, which must be kept clear of moths and webs. What shall I say of the ornaments of the ceilings and the paintings of the walls, except that riches produce folly." In a vocabulary compiled by Alexander Neckam, a popular scientific and educational writer, who existed between the years 1157 and 1217, for the purpose of teaching the elements of the Latin language,* are described in an orderly arrangement, all the various articles coming under common observation in order to give their Latin synonyms, which are often explained by an interlinear glossary in the Anglo-Norman jargon of the period. In one portion of this work the compiler gives a We have here the process of building a brief account of the process of constructing an house, as we had before that of building a Anglo-Norman castle, which, I think, will be castle, and it is equally interesting in its considered as possessing some curiosity:- details. But by far the most remarkable cir"If a castle is to be properly constructed, let cumstance connected with it is the reason it be surrounded by a double foss, and let the given for making the walls lean outwardly, site of the place be strong by nature, so that because, since every heavy body tends to a the motte (or mound) may have a convenient centre, they ought to represent the radii of support upon the native rock, or in default of the earth. This principle, that every heavy body natural advantage let the assistance of art be called in, that the mass of the wall constructed of mortar and stones may rise to a lofty work. Upon this, let there be raised a rough hedge, which must be well defended with quadrangu *"Summa Alexandri Neckam de Nominibus Utensilium" (Alexander Neckam's Classification of Words applied to Useful Things and Purposes), Cotton MS. Titus D. XX. British Museum. tends to a centre, is spoken of as one known to everybody. We have thus revealed to us the extraordinary fact, that the doctrine of gravitation was known to Englishmen of science full five hundred years before it was discovered by Newton! +"De Naturis Rerum," MS. Reg. 12, G. xi., fol. 79, ve. British Museum. A (To be continued.) B VELOCITY OF ELECTRICITY.-In the supplementary volume of the "Encyclopædia Americana we find the following interesting statement:-"A copper wire, one-fifteenth of an inch in diameter, and half a mile long, is insulated in such a manner that its parts are not in contact with each other, three breaks being made in it, one near the beginning, another near the end, and the third near the middle of the length. These breaks are then brought near each other and arranged in a vertical line before a small mirror, which can be made to revolve, by means of watchwork, at the rate of 800 times in a second. When the mirror is at rest, the sparks appear one over the other; when in motion, the reflection of the three sparks from the three lines of light in the mirror indicate that the duration of the discharge occupied an appreciable portion of time. The spark at the beginning of the wire was vertically over that at the ending, whilst the spark at the middle was thrown a little to one side, which proves that the disturbance of the electrical equilibrium takes place last at the middle of the wire. By measuring this deviation and comparing it with the motion of the mirror, Professor Wheatstone found the velocity of the discharge was about 288,000 miles per second, or greater than thato f light through the celestial spaces." GALLERY, &c.-A return moved for by Mr. THE BRITISH MUSEUM AND NATIONAL To describe an equilateral triangle upon a rooms, 4,126 to the sculpture galleries, and given line. 4,390 to the print-rooms. The number of visitors to the National Gallery in the year 1846 amounted to 608,540. The pictures purchased for the National Gallery since August 6, 1846, are three in number-viz., 1, Philip IV. of Spain hunting the wild boar, by Velasquez, from Lord Cowley's collection, for £2,200; 2, Annibale Caracci's Temptation of Anthony, from the Earl of Dartmouth's collection, for £787 10s.; and 3, Raffaelle's Vision of a Knight, from the collection of the Rev. T. Egerton, heir to Lady Sykes, for From the points A and B as centres, and £1,050. The number of visitors to the arwith the distance A B in your compasses, mouries at the Tower of London, in 1846, describe arcs crossing each other in c. Draw amounted to 52,287 only. Fig. 11. Fig. 12 is a diagram and outline of what is termed the volute or ram's-horn turn of a running scroll, to produce which it is necessary to form a square; then divide it into seven equal parts. From the third division on the base strike a perpendicular line, and then from the half of the side of the square marked 3 a horizontal one intersecting both, the point of which will be the centre required. Take half a division as marked on the base, and strike the small circle, after which form a lozenge, and divide the internal diagonal lines into six equal parts; then place the point of the compasses at fig. 1 and strike the arc fig. 1, which must be terminated at the dotted line A. كس Fig: 12. of the line, thus producing what are technically called "shoulders." The arc 2 is now to be struck from fig. 2 and terminated at B, from fig. 3 to c, and so on until the volute is completed. The other portion is the diagram filled Much of the accuracy of the volute depends with scroll-work, representing the various essentially upon the lozenge in the centre of forms of leaf necessary to encircle the vothe small dotted circle, which, if not executed lute. The same plan may be carried to any with precision will not admit of the juncture requisite length by merely alternating the sciences in such a manner and in such a degree as to prepare him for all emergencies in which he may happen hereafter to be placed. A Venus di Medicis would not have lived in stone, Had not the sculptor known the place of each artery and bone. Chemistry may also be studied with advantage. Dr. Taylor says, "No science is of more importance to the designer," and in this remark we fully concur. "A designer making a pattern without knowing the means by which the shades he introduces can be realised, is almost certain to go astray;" and for this reason all the designers for silk at Lyons are excellent chemists, as they have, for the most part, been educated at the admirable school at La Martinierpe, where a very extensive and practical industrial course precedes, and is made the basis of, artistic instruction. a correct judgment upon their own goods, That In concluding, this week, we cannot do bet-arts, that the science of perspective may be ter than to present to our readers the following extract, from a paper lately read at a meeting of the Architectural Association, which will, we think, bear out our views on this important subject: well understood, for without such truths invention will never appear nor accuracy of form be attained. There is no greater folly than pretending to draw without this foundation, and though geometrical construction and perspecWhy should the different branches of the tive is the true foundation on which the drawarts be slurred over as they so generally are in ing of all forms must be based, they must be educational establishments? Are we to rest taught in reference to real objects. All insatisfied that form and colour are only worth struction should be given upon principles an exercise of accomplishments, and that con- immediately derived from nature, when its apstructiveness is unworthy of a legitimate exer- plication should be shown upon models or cise in the different schools? Let anyone who natural objects, and explained clearly in order has a common understanding of those faculties, to prove the truth of those principles. Withexamine the drawings as they are called, that out this knowledge, the student must expect to the pupils of both sexes bring home half-be always in confusion; and it is in conseyearly, and they must conclude that so much quence of the want of this valuable information paper, pencil, and colour had been destroyed; that there are so many works of art that the mind injured, time wasted, and money are false representations published, which thrown away. Such a loss of intellect is ex- is an evil of great magnitude, abusing the pubceedingly discreditable to an intellectual nation. lic mind by inducing it to believe in error Our foreign neighbours do not act in this instead of the truth, which to the uninitiated slovenly way in artistic instruction: but we do must work a serious injury, as all falsehoods not like to adopt that which is good in our will do wherever they are brought forward for foreign neighbours' educational systems, be- public approval and encouragement; but the cause they emanate from despotism. Let us take rising generation will not much longer be corthe good from all, and leave the despotic quali- rupted by false art, as they are to have their ties where we find them. It is evident enough mental powers soundly exercised in artistic that we are not right, or our manufactured matters, and to a certain extent they will in goods would not be so defective in all artistic time possess a certain judgment, and be points as they are in form and colour; and enabled to distinguish accuracy from inaccuparticularly as regards colour-the most fright-racy, which will oblige the producers of inacful arrangements and contrasts are made. In- curate art to become accurate, and no longer to deed, they are too often so devoid of harmony, abuse the public mind with their mischievous that on beholding such discordant and out-pretensions." rageous colours, we can hardly consider them as the productions of a civilised nation. That such unnatural and ignorant productions are the result of uncultivated minds in form and colour, there can be no doubt, and why those mental powers should be allowed to be so falsely exercised is this, the producers of such unintellectual wares are ignorant of the principles on which such articles ought to be produced. They know not what are the proper and harmonious arrangements and contrasts, the apparent forms, light and shadow, texture, and the rules for producing them. Now, if the master manufacturers are not soundly informed upon these subjects, and therefore cannot pass TO REMOVE PAINT LETTERING FROM WIREGAUZE WINDOW-BLINDS.-Hold each portion. of the letter, at about an inch distant, over the chimney of an argand gas flame. In this manner treat every letter, or every part of the paint ornament, until the oil with which the colour has been mixed becomes decomposed and charred. Allow the gauze to cool, and then wash it well with strong acetic (pyroligneous) acid, rubbing it occasionally until the paint be removed. Next wash and dry the blind, rub off adherent rust by means of a wire or hair brush, and polish with black lead. |