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Show SCIENCE NOTES An Interesting dredge, which Is anto-aiatle anto-aiatle In Its operation, has been working on tbe river Volga, lo Unssla, for some time for the porp.-?o of maintaining a V-veJ river bottom by moving the dirt from tbe high places and depohltln it at tbe low spots. The dredge la the In-'ntloa In-'ntloa of n Uusslnn noblemau. Uxrn Nicolas Tomlnt. Teneath tbe craft there ts supported a screw, by which the soil is gathered up. There seema to be almost al-most no limit to tbe width of the channel chan-nel that may be cot by this dredg. The screw s cutting surface may be incrcasel as desired by the addltlou of boctlons so Unit in some Iiibtanccs as much as 230 feet has been operated. The Inventor Is 0 the opinion that this Is not of the pos-s'ble pos-s'ble length. He says he sees no reason why the screw should not be made fwo feet long If found desirable. Tbe power wblch drives tbl dredge Is derived from the current of the strtum on wblch It Is at work. In operation thee sections are secured together to the desired length 00 the shore and then launched Into the stream, where the line of screws Is secured se-cured hi beneath the dredge. When tho craft U moved Into a position where tbe full force of the current Is encountered, the machinery Is automatically BCt in motion and the work proceeds. Thrs novel piece of mechanism has attracted the general Interest of engineers abroad and bus been heartily Indorsed by many of them By a recent Improvement It la possible to deposit the Boll on scows for removal to more distant points .where it presence may be desired. By sub-stltnting disks of curbon for the rods of the snme material it bas been made possible to greatly reduce the sbie of the arc lamps and at the aine tiro to present n lamp which will burn .V per ceut. longer without renewal. Thcso are Important Improvements. The cul-cleocy cul-cleocy of the nrc lamp has always been limited by reason of the unequal eon-sumption eon-sumption of the carbon rods, which have had a tendency to burn faster on oue side than another, and In this mauner a perfect per-fect contact of the two ends was possible possi-ble only occasionally. In the new design de-sign which makes use of the carbou dlaka tbe latter are revolving all the thno the lamp Is In use nnd the arc is made at the edges of the two disks. The 10-nni-pere lamp of this design are but 20 Inches over ull. Sanitary enr strips for those who aro compelled to stand In the slreet cars are being tried jn Mmc of the uuder-grouud uuder-grouud cars In use lo New York. The new 'strop" consists of n hIcm-I rod which Is suspended from the roof and having a porcelain handle at the lower end. Tbeo may be kept absolutely clean, whereas a recent examination of a cor strap which hud been lo service but comparatively short time was found to be reeking with all kinds of germs. The cost of filtering water by tbe slow ! "and method Is given as follow in the I jrw report of the Lawrence, Mass.. water board. During that year 1.103.CO5.ST0 gallons gal-lons were flltere.i at n total cost of fn,. M-I.W. or about Jfi CA per 1.ot;r.non Ion. The Itemized cost per l.nno.tuo j-illou was: Removal of ce and m.-vw. $." OCM scraping. $l...v,: sanding. ?0.7. washing and conveying annd. SI sr.); niter nam-tennnce nam-tennnce nn.i extras, II.Js.sl; curj of ground, f "J.rr.M. |
