POPULAR SCIENCE.

Gisborne Times, Volume XXX, Issue 3488, 30 March 1912, Page 3

POPULAR SCIENCE.

BETTER WHILE YOU WAIT An enterprising American butterman has recently added to bis liefc of electrically driven appliances a 11 horse-power motor for driving a churn. His patrons purchase cream of him., and for a small charge have it made into- butter on the spot. The me-: thod is not only an excellent advertisement for the tradesman, -but is also instructive for the children and others in the neighborhood. the PASSING OF THE LAMPPOST. Lamp-posts are to disappear from the streets of the City of : oil don and all lamps —ex ■ pt ill —' -»il. bo suspended v- r 'he centre of the read and- pro- - i 1 u n.h lowering : < 2 r. I.ii-s is ere of ih« n.mcioa* features of a new ighxing scheme adopted by toe C v >:\i ci Coupon Council. ’>.pe -*.ii .1 s w:n tj, t . centrally hung ami:; In,-.. >-,. :1 j o;.i- at the St. Paul’s » ,-t• < c CLc<,n--side and m King l)K ; Gannon Stress, a.vj Mr J,..<; nn . ton, chairman at the Streets 6 mii’iitee, Mm; ij.ey Ud m ,. t v . :i h universal rarer among che oublic. I lie only argument he <r4 " l ear.) against the removal of t ) K - lamp-post* was tnat after a heavy banquet thev Yvould be missed. CniM'dio new scheme the lighting of the City will ae tan-ly equally divided between"gas and electricity, and. it is claimed that while tiiere will he a net annua] savinrr ox - j1 Tiie ilhimination vv'jJJ oe increased from 06*. ca^di* 5 power to 1,270,160 candk->/Vwer. ~ ROAD REPAIRING A. system of road patrol has leer introduced in some parts „_f America hich .should move not only efficientbut- economical. It operates G n the theory or that. old adage. -X stitch in time save; nine,"’ and the aim is to prevent the little, defective spots fromgrowing into oig and costly ones -An autotruck, which is capable of carrying sufficient tools, road material and la borers is assigned to a certain stretch of road, and all small holes are attended to before they have a chance to spread. One of the vital features of tile model n j’oad tor motor travel i < the surface, which is (subjected to the suction of tyres travelilng a high •speed. The sealing process in use on the roads .in Los Angeles county is a vist- improvement over the old style, road sprayer of crude oil. which operated by gravity. _ The present device spiats liquid asp.-ialt at a temperature of 212 degree, s Fahrenheit wit) such uniformity as to cover a equate yard of surrace with so small a quantity of liquid as one-quart?; 1 of a gallon. There are no streaks left.”as m the old gravity system, as the atomiser operates under a thirty to £ftvpound piessuro per square- inch. This is important, as any clogging <-f the sprayer would leave a weak spot in the road. TO DETECT ICEBERGS. 1 lie method hitherto generally n: use of taking water temperatures on transatlantic liners to guard againstthe approach of iceberg.; has been to dip water up out of the sea and take its temperature as quickly as possible. By this method continuous measurements cannot be taken, but a- mistroth ornicnie ter has now been invented bv a professor of AlcGiJi University, which, with an instrument similar in action to the oscillograph attached, records the slightest changes hi temperature by drawing a continuous curve. -- Ihe thermometer indicates exceedingly fine differences in temperature by means of the variations in the resistance of a coil of wire, these variations ssrrin gto indicate the changes of temperature of the medium m which the instrument is immersed. The ceil consists of 253 ft-. of pure-iron silk-covered wire, wound on a copper cylinder and enclosed in a second watertight copper cylinder. If an iceberg is large it may be detected mary miles away by the coolness it-causes in the water. THE PRESSURE OF LIGHT. Divide a bail c-f lead weighing one pound into one thousand little balls. The total weight remains the same, but the surface lias -been increased. Divide each litle ball again into one thousand smaller balls. The resulting one million balls stell weigh one pound, but- the surface lias been enormously augmented. Carry this subr division so far that leaden particles are obtained measuring one twentythousandth of an inch in diameter. Each one of these particles, if placed into interstellar space, will remain stationary because its weight- (gravitation) will exactly counterbalance the light pressure of tlie sun. If subdivision be carried beyond that critical diameter, light pressure will wrench each particle from the-grip ot solar gravitation and hurl it into space.