Scientific and Useful.

Bruce Herald, Volume XXII, Issue 2263, 8 May 1891, Page 5

Scientific and Useful.

' '• " Tiie prerWling' dolour'bf the African 1 or Cape (diamonds.ii jrelibV, rUngro'g-from dceporatige , tQjlight merging into .white. i.i,'.- h'.ivil HifTOJIBrVBiKTOESi '■ ''"■'

:THe Poßtmiast'erlGreneral, 'being desirous of effftotin gl i fln^iinprovemervt in the apparatus np^.jin^ueejfo^.it^ansferiCing roail bags to and t from 'the "mail trains, whilej; in motion,, will be . glad' fco, r'ic'eive zithei suggestions For lmprov;in^';ilij( o> Jlesifchs' of ! ai more ' perfect; form of apparat ua.i i Hei i is* < prepared 'to - give three prepiiu^-rrpnerof oneiof £100, and one T of,£sQ^-for f .th^ j three,pipppßa i lß v wb,ich he may 'consider the D6st of those brought under his 'no'ttee 1 ;' but; tW first premium— that of £250— i will 'Onl^ be' awarded ' in the • event of the (adoption fofc the mail service of 'one of the :j „. ; , ' -, '; : ■ ! A,' 810- STBEI» BPBING. iA> great; feat in metalrworking, according to ,the Ameniflan Manufacturer, was recently accomplished at the Superior Mill, Allegheny, .T"a. The feat consists of rolling a strip of sfeeel / frir. a spring 6in. wide, Jin. thick, and 310 ft. long. This work was successfully performed, land the spring properly tempered , at the fir ( st effort. That establishment has since received, a large order for such springe, which are designed to enter into the, construction of a new cartnotor, for which a ereat demand is anticipated. The order h«d previously been tendered -to all the large English and Continental, works, noae of which /would undertake to do it. THE " STAB BAM." One of the most important munitions of 'war which, wilj be henceforth manu r actured at Wodlwichis known as a'star ball!' This surpasses the almost Obsolete parachute firelight which uepd'to be charged in the air, and opening at a. considerable altitude, formed. into a parachute and lighted up the enemy's camp. 'Unfortu'naiely, the wind often drove it over the honie camp. To' surpass this, the star iballnhfts been invented. This will be discharged from ( a howitzer. The action of the feuse onuses a perfeot shower of sparks to full mili-s from the spot whence it is discharged, ihuVlightirig up the whole of the country side.

SENSB OP SMBIL IN STAK FISHES. A number of experiments with one of tbe star fishes-— Asterias glacialis — show that, when the aninal \a eioi'ed by a desire for food, the sensations which it obeys are perceived by the extremity of the arms; but others show that it is tbe sense of smell and not of sight that guides it to its food. The tentacles near the eye-like epot, which are useless for locomotion, were; removed from a Btar fish, which, for a month or more afterwards, nerer abdwed the least excitement in the presence of either living dc dead food; the retention of Ihe ocular spot jnakes no difference. It in clear, then, that the 1 sense of smell is not diffused in statJfi-bes, but ia localised in the tubes, unsuitable for locomotion, situated behind the eye spot.

i " A MAN AND A BEOTHKB." T-litS JJev. Dr. Dullinger, in a recent lecture on the,'-' Wit and iWiadom " of Spidere, " 'lowed ",,fchafc these araohnidae " occupy a high place in the, intellectual scale, although ■their ' wit and wisdom ' diffe? with the several specieß. Their wisdom is more than merely inherited instinct; it is mind, differing only in degree from that of man." Dr. Dallinger exhibited on the screen the aeries of procef sot by which a spider, makea ita wonderful net — an operation said to occupy the spider less than an hour. The Doctor further remarked that, viewed through the law of creation — which is the law of, evolution — all backboned ahimnlß are now held to be the outcome of spider-like forms, bo thtt the 'spider now becomes " a man and a brother."

THE PIBEXE9S 10C0M0TITE. M. C. Rolland, in Mons, Belgium, has constructed a firelesi locomotive for use in mines. It is provided with a tank that holds an 0550 cubic meter. ' The water is heated to 205° 0. (or an absolute tension of 16 atmospheres) by a boiler placed on the surface ; it is sufficient for a steady run of 3 to 4 kilometers. The heating is brought about by means of steam jets, as fi¥sfc proposed by Me Bede, Belgium. The heat thus stored up in the rather small space gradually evaporates the water required to run the machinery. At a speed of 2 meters par second, the locomotive works with 6 horsepower, that of a horße being generally estimated at from 0 9 to 10 m., so that the locomotivo, .wofkin? day and night uninterruptedly, takes the place of from 12 to 18 borees, besides a good many labourers. Tbe Baving'is calculated to be 200 dols. per horse dispensed with. As a further advantage, this locomotive secures better ventilation. The weight of the locomotive is 3000 kg. — Scientific American.

„ PETROLEUM AS FUEL. As a consequence of the continued increase in the price of coal, the übp of petroleum as fuel appears likely .to be considerably extended. On ship board the saving in weight and space occupied by the fuel per voyage, or with the same fuel capacity, the possible increase in the endurance of our warships, are advantages, the importance of which it is scarcely possible .to overrate. Experiments with petroleum as fuel on warships have been made by tho Italian Government during the last? year ior two, with, it is said, very success- , fill results, and now; following this example, j the British Admiralty are apparently deter>m'in(e<i to experiment in this direction. It is stated ! gunboat is shortly to be fitted jupi faith ;an improved oil-burning furnace, and t t(at, with, a, jyery, little labour the apparatus ,cp,n-be substituted, for the ordinary bars of 'riaVai' furnace's, 'so 'that fcHare is no reason whatever 1 Why the vessel should not carry ! bo^h i equij/ments, so 1 as' to use coal or petroileum, waetej or prude oil* according to the cost of, fue|ion,a particular, Btation. — Mechanical ■World' ', •..'. ■ i>i f:\A- '■■■■ !'j; ?■■'. f . ; , iy . i. ;.|^B,. ( TBETH GffißMS. I -cOMwi 'development of teeth germs from 'infandj:*o/m4mra' lifejia -writer im the Pitts-, jburg D,isp,atcfy, , $un£s,, is- one of the most interesting phases 61 k human growth, Pa.BB jth'e^ I ng%r ni llpDg [! the 1 tiny jaw of the neyricbatfer. •Q^oVmiT^is tbere'nothing whioh presages [futures .tfeetflr, bud the jawa themselves pqem" t&QnidtfUcKtja p,ndrfrail-ito ibecoaie the 3ocketsior jauch hard- wording, .portions of jthe anatomy- v Yet we are ' assured that there kry'%tty-W6 n 'teeth' M germs hidden there. tEtfetffcy.bf ftnfcm'We J for ' the temporary teeth, wijjh whioh ipfdue time, the! child, will begin to g^JfnPf us h SW n£"? ?ay. i-th^ough; life; the others incmde tthe permanent -sat; , and *he ( nbiar^'faone of wnich begin to make th^eir pfesenb'e t %n l o\*n' y unttl 1 the child is 'six' years' bldyand the 41 'wtß&om^lteebh ' do not usually Ipge^r jj%qfc}l , ); abput«;otbiß dge idf eighbeenv the lifctlQ -pplp germ growa and develops till it; •aiSprqkimales .the I ' shape of the, tooth it is to beSMe fitiinkt b^ltf^o calcify "fproiuig the r j<a¥.t J of tne^croVn, wbilci the'enahidliß depoStetd Jbyrfa'a ihdepepdent ' prbcessi The < of {^fprown, attains itfljfjuUsi^e.beforei the propess of elongation oommenpeß. Then; If, pushes iUjVay outward ,' through. tib.'^ J guiiiV i 'abs'o):m'ng t ifB ff tissue J aa it f advances tinjthe l out, tb the imotherl^rejkt delig^i e-.'i ni ■" - . !