Scientific and Useful.

Lake Wakatip Mail, Issue 1502, 24 October 1885, Page 4

Scientific and Useful.

SHARP PIIOTOGRAPHS. A n 1 of a French train hp,* bogn tnkv-n whilst traveling at, the rate of 42 milt's per i our. Some slight blurs appear in the photo, otlipcw'so it is very good. The train ppeara to bo standing still. ICEBEEG DETI'.OTOR. Mr Frank Delia Torre, of Baltimore, pr;)« Porps a method of detecting the proximity of impediments ouch ns icebergs at seu By

ra'-an* of t xperiments with blank cartridge. ! fir d from a mu«ket with a speaking trumpet ■ attached to the muzzle, it has been foun 1 that ! even passing tug-boats will give back echoes. A steatn «histle or siren with a projecting f apparatus lue the speaking trumpet at'ached, | would, Mr Delia Torre argues, prove as | efficient as a gun. SUB SrKFACE TE3IFKEATUBK3, The German Government are having a boring made near Schladebaeh for the purpose of determining the increage of the earth's temperature. The depth reached is more i than 1392 metres, the lowest depth yet ob-

tuined by b tring. The temperature at s;ic'es«ive depths i 9 ascertained by a new mercurial thermometer of most ingenious cjnst'ue'ion. determined that the temperature at thn depth of 1392 metres " > 49 decree* C, or 120 degrees Fa'ir. A.t t:,ia rate of inrrea-e the boiling point of water

I should be reached at a depth of 3000 metres. DANGEROUS BfSINESS.

X. D. Join's, who transports the nitroglycerine for the Warren factories, makes a trip Jovrn the river in a little beat erery two months. He takes about two tons of explosives, aiul on his lust trip, according to his statement in the Br.idford Era, he narrowly esciped b.-ing run down by the steamer Emma Graham. He stated thaf the pdots seem to delight in running little boats down, and some day this wi 1 be done to the sorrow of some of them, since 'lie amount of glyc r-

ine on board would be sufficient to tear a boat up so fine that it would require a searchwarrant to find the splinters. MONITOGRAPH. This apparatus is a small improved cimera which may lie advantageously used a subs'i'ute for the black cvnvex mirror ihat landscape painters so'no imes erapl >j. When th"-e l i'ter are used it is necss irj to turn the back on the landscape, and a reversed linage is obt iin' l. A.jain, as the class is

hlni-'i, so us to prevent double refraction, the eca'e of t. nes is not accu ate, unci furnishes verv dis tdvanag-ous data <o the painter. With the in nitograph, which the artist may :itl]v to t'.e Oi.se' ilj.it 8i; puts his pi -tire, we _'>t a reduc-d imag •, but one tlia' is vorv accurate in all its d.-tnils. Tne apparatus is plieed to the right of the aitisf, who thus i Ins before his eyes the scene that he wishes j to represent, while at th-sime time the re- j du.-e.l illume is i.ot r v ■ rsed en the ground giass. 'lhe luminous iirensity of t'ie image is equal, ai.d the tones are true to nature and may be reproduced upon canvas. TRIPLE SIIIPS. Mr William Coppin, writing to Enqinet'ring, says : —Having had a long experience in j the construction of ships alter the present type, and having a!so, by models, tri"d many • experiments to obtain the highest speed, I have designed and pa'ented a triple-hull, d j ship, which 1 believe will be the ship of the luiu'e. By having three liu Is instead of one, j 1 have been enabled to reduce the angle of | re.-istan.'e to the lowest minimum. The j centre hull is shorter than the outside ones, j and a- a' each end of this central hull there is j a full poA'er propdior worked hy two sets of ; compound engines, with boilers quite indeoeu- 1 dent of each other, it is evident that this provides agiinst any accident, and briugs the

pro;itllin„' powers Iron the end (o d arrangement) neurer 10 the centre. In a heavy Bea, always dmgerou?, this plan prevents the racing uf the engines. ELECTRIC FAN. A very refreshing invention, especially for the hot weather season, is the electric fan. It consists of an ornamental standad, about a foot high, on which is mounted a screw propeller tan. On connecting the wires of a battery with the standard the fan revolves : rapidly, and delivers a cool b.-ecie in any direction desired. The upper i art of the standard, on which the fan is carried, is hinged, which allows of the adjustment of the fan to I

any de-ire i oblique posit on. The battery is ' '.•ontairied in a lit tie boi 4j inches squire and ! the Bitue depth, holding liquid enough to run j

the fan for several hours, when it is poured out and replaced by a fre h -u >ply. We hare had one of thes>> fa'.# running on our desk for several dijs pist, and it gives muoh

satisfaction. They are made by Stout, M'adovvcr.ift and Co, 2L Ann street, New Y.>rk, whoso excellent and reliable work in the line of small electrical lights and other instruments ;» well known. —Scieutijic American.

SALT A 8 A IIEBTROYEB OF THE TELSII At a recent meeting of the New York 0 lontolog cal Society, l)r £. Family Brown said:—l will venture the assertion that the excessive u e of common salt is one of the tan factoi a in the dcstructi m of human t e h to-day. 1 hare lately procur-d some statistic from tlio Sandwich inlands from a

g.-n'leman who has beeu there, covering a p rioi of over forty years, that are very suggestive and interesting. Within that time the teeth of the Sandwich Islanders have decayed r -pidly, an 1 since they hare begun to dec iy it h is b >en notice I tint ttie natives are in the habit of biting off great chunks of silt and eati >g it with their f >od. According to most accounts the teetii of the Sandwich Inlanders were formerly the most free from deciy of uny people on the face of ttie earth. You will find that people wnoeat a great deal cf sugar and a great deal of salt are often entirely toothless. People who eat an excessive urn i"unt of silt are tempted to eat lirge quantities of «c.indv, pickles and vinegar. There seems to be a craving for those substances aftor the excessive ÜBe MOVING A N'INETT-FOOT CHlitS'El*. One of the most difTl.-ult transfers of heavy

structures yet attempted was successfully completed in Salem, Mass , a short time ago, where ;i bri'-k factory chimney, 90 feet high and only (5j feet in d.ameter at the base, was taker, up and moved, with the aid of 6 men and two h irses, IUO feet and safely deposited upon a new foundation. It was estimated that a sway of three inchng would bring it to the ground, so that great precautions had to be taken to prevent any lateral movement while being s'lifted. A ca_'e was first built around the chimney, consisting of horizontal timbers supporting shoies, which extended 23

feet up the sides of the shaft, and wero reinforced by a second set of shorter ones beneath. After these wero in place holes were cut in the brickwork and needles insetted, under which 3-i screw jacks were placed, and the shoring and shaft rai*ed high enough to allow a rough platform to be constructed under them and rollers to be set in place. The platform extended to the new position of tiie chimney, and by levelling it carefully and employing a

large number ef rollers, the load, weighing 130 ' torn, wu eaiily movod into plsoa,