One of the most singular wants of man, but especially of woman, is to devise means to ascertain how her personal image afipears. From the fountain, in which Narcissus looked at himself, to the bureau with lookingglass, many plans have been tried. The first artificial mirrors were made of metal, and were discovered at a very early period, and must have been contemporaneous with the art of polishing flat surfiwes. At this date, looking'glasses are used every where—even as ornaments on horse collars, in Europe. As ornaments, lookingglasses look beautiful, reflecting, as they do, daylight and artificial light, and thereby flooding sumptuous apartments with a deluge ot light. They seem to enlarge small apartments. When not silvered, but simply polished and left transparent, they give to store fronts and windows a cleanly and bright appearance not attained by common window glass. Used between two parlors, they are one ot their most beautiful applications. Since the wonderful invention of Daguerre, and especially, latterly, large quantities of small cast glasses are made for photographic purposes. As to imperfect glasses, not suitable for polishing, they are used to form-walls through which light freely traverses to rooms which require to be lighted but closed ; they may also be used for floors, roofs, etc., etc. The use of lookingglasses has increased wonderfully, and this increase is owing, in great part, to a notable reduction of price, the consequence of an invention of Abraham Therart, a French artist, who, in 1888, conceived the bold undertaking of casting glass as it was practiced with metals. This new manufacture made such wonderful strides that, three yea14i! afterwards, a company was formed to carry out this new manufacture; and, in 1691, the establishment was transferred to St. Gobain, where it is in existence to this day, and is manufacturing a very. snperior article. St. Gobain, by the beauty of its glasses, by their relative cheapness, and the ability of its nJ3,nagers, has retained the monopoly, almost exclusively, of the French market, and has, besides, maintained a rank abroad not to be excelled by others, notwithstanding the active competition o1 Belgium and England. This factory has six strong competitors in England,especially in lookingglasses used for windows. The oldest is located at Raven Head, near St. Helens, South Shields. The Thames Co., the British Co., and three other factories, two of them situated in Lancashire, and the last one at Smit.herick, near Birmingham, with the two first named, manufacture more than two hundred thousand square meters per year. The j most important factory of the Continent, after St Gobain, is ' ttI t Sajnte ?tIarie d'Oignies, nea]' Cha.rleroi, in Bel " 81 ua ec a gium. . 1 In 1860 St Gobain alone manufactmed two hundrec. thoueel " . ' PI" the six I?n lish factori es. three hundred sana s?ua:e met ? S, , g . h ' - d "t and fiity thousand meters ' JJ clgmm one undre ana en ' . ' thousand, a ?d Manhmm sev, nty 3Fnd . 1 ." I' The 100km gO'lfl ss manuJactnrcs In ' ran ce Iflve a capl,a : . . ,, ' , 1 5 000 ' 'k ' . of 50 or 6 0 ImP IOns ;C11lTa o'cd and emp oy WOI men 81mother L . ? M , ' . 1 d' ply on the manufaduro of the glass lJI'o per not lUC. u mg , " . h f b' . . d 1 tnose employed on t'w separate bran c es 0 usmess "pen ein ' , , h . ' , h lng unOll it This bran ch of maIl lliact,ul'e 'as ati mneu sue , . ' 1 . ' . 60 ' t. f f . t' tl t at tItS ,c av Pl'lces are per cen t, apas ,,1te () per ec lOn , ?'. . "' '_,: .. " 1 11 fi lowe r than twenty year., ag o and i)"" 1'''' cent ower t an ve years ago. From experim ents made, thtl fo llowing show," the relative noposition of French and Belgit n Ulanufactllres. To manufacture a sq uare meter of glass, th e fo llowing is required : (In Sainte Marie d'Oignios, Bel gi um.) To melt 118 kilooT., soft coal at 13:. 50c. tUll . 2f. 38c. " polish 195 ,? " " 8f. 580. tun . . . . . . . . . 1f. 65c. Total . . . . . . . . . . . .. . .. ........................ At: 03c. (In St. Gobairi, France.) To melt 1 80 kilogr., soft coal . ... , . . " ............... 3f. 960. " polish 195 " . " . . . . . . . " . . . . . . . . . . . 2f. 94c. Total ............. , ...... , ........ . ............ 6f. 90c. If we complete the estimates of the last price by addin g the pri ce of the chemicals, the sand, the chalk, and the potmaking, and by adding the labor, we arrive at the following cost prices of one square meter : Sainte Marie d'Oignies, Belginm .................... 17f. 540 Ruquignies, France ........... " .................. 20f. 34c. St. Gobain ......................... .............. 2lf. 61 c. Cirey . 2ilf. 97c. Montlugon 21f. 61c. By adding the interest on the capital invested , the lust price is raised tc 27 or 28 francs per meter,and is sold in Paris at an average of 34 to 35f:" It is a wellknown fact, that the United States, with its immense resources for this branch o f manufacture, 1ms not succeeded, yet, in producing a merchantabl e articltf in this line. What is wanting, then, to manufacture it successfully here ? We have sands, beautiful and much superior to the European article, although England draws :1 large quantity of it all the way from Australh ; we can manufacture our sodas in this country as cheap as in Europe ; we have coal in plenty ; we have the capital ; thereforo.what we want is men capable of managing the work and skillfnl workmen. Ability and love of work are oftener wanting than capital. '1' his class of m en, however, is often left .at the mercy 0.1: men unacquainted with the business, and oftentim es ot lJad. f!Lith, who can not, or will not, wait for the slow but sure profits of labor, and who simply take hold of the bUl3iDf'SS as a speculation, as it were, ca.rin g noth ing abont the Hrtistic excellence of thei r employ ps,h ul wOllld part with them at flny T" tim" if they t,hought they ,could malw a (lollar by ii. nese, I think, are a few of the reason s i;hat discoumgc skil lfnl men from coming to this country. it lIdwoman, A manufacturer of lookingglasses would find it to ds advantage to locate near the ocean, wliere he could receive his raw materials,and would he near larfge markets for hj) wa.res, and could, also, make up some of the materials used in manufacturing. Saint Gobain, in France, mannlacturi s its own sodas, emery, colcothar, and tin sheets. Tuey luy the tin in Amsterdam, from the Dutch Indian Company. This company only sells at wholesale. They get the mercury from Spain. If we cite these facts,it is to establish a comparison between a factory located in Europe, and one in this country, and to show the advantages of a location on the ocean border. We will give an example of these advantages. S()tas might be made on the spot, and would thereby save a vsist amount in freights, as soda is obtained from sea salt by transforming it into sulphate of soda, then the sulphate into carbonate. In this latter state it contains a large quantity of water—from 62 to 66 per cent—so that 100 pounds of tbis salt represents only 34 to 38 per cent of dry caibonate of soda. A factory, making this carbonate on the spot, would save the fixiight, not only of the pure carbonate, but,also,of the 6-10lhs of water it contains.We have, in some of the Southern States, sand suit able for glass-making, and, also, fire-clay suitable for making the pots (crucibles), which have not been tried properly, heretofore, but, by being properly mixed, would answer the purpose as well as the German clay that we import at a heavy coft. We therefore say, unhesitatingly, that a lookingglass manufactory, well managed, must be profitable in this country. Washington, D. C. J. P, COLNE. WATCH-SPEINGS.—It has recently been discovered tliat the springs of chronometers and watches. which are constmcted of steel, are frequently magnetic. Steel is at all times liable to become magnetized from causes beyond man's control. Watch-makers are advised to test their springs as to nagiiet-tm by placing them near to a very small and truly balanced mariner's compass. If the spring exhibits in none of its circumference any tendency to move to one pole of the compass more than the other, it may be crllIsid, red free from magnetic influence ; on the other hand, if the North pole mover! to one part, and the South pole to the other, the spring is decidedly useless ; for in whatever position the time-keeper may be placed with such a spring, it will be afiected by the earth's magnetism.—Septimus Asquare meter equals one ana -one n'rth square rara. iieari;. A iio trammels two ne pounds avoirdupols nearly it centime is on undredth of a franc.—Epe