A NICE CALCULATOR.

Grey River Argus, Volume VII, Issue 520, 18 May 1869, Page 4

A NICE CALCULATOR.

(From Once a Week.) Softe weeks ago we were startled by an announcement in the military and naval intelligence; of the Times, that an instru • ment that aould measure the hundredthousandth part of a second, was employed .by the authorities at Woolwich, in experiments «h gunpowder. At the time one ■juight hftve thought that the leading jtpurual was merely laboring under one of .those fit* of inaeenracyto which we are all occasionally liable, but having since Jiad an opportunity of examining the intferranfint in question, I am led to believe that its powera were not overrated. This Machine is tfsed for measuring the velocity of a projectile within the bore of a gun, pntl *s far as I could judge is quite capable of recording the time that a shot travelling at the rate of one thousand feet a second will take to pass over one inch. The apparaiuß consists of a Bystem of toothed wheel-work, beautifully made, and driven by means of a descending weight. The velocity with which each wheel travels is progressive iv the proportion of five, to one ; that is to say, each wheel travels fiv« times as fast as the one in the rear of it The last wheel turns a spindle to which »ix brass discs are attached, each disc being 36 inches in circumference. When the machine is travelling at full speed these discs move at a rate of about twentyeight revolutions a second, of in other Words, about one thousand inches a second ; an inch of disc therefore, represents the thousandth part of a second. The passage of the projectile is recorded on the edge of the disc by means of a spark derived from a Rhumkorff's co ii . thus the interval between two sparks denotes the time taken by the projectile in passing over a known distance in which it ruptures two galvanic circuits and causes a corresponding number of sparks. Each disc has its own coil, marker, and galvanic circuit, by which means the time of passing over five distinct spaces can be recorded. The actual rate at which the wheels are moving is ascertained by means of a stop-watch attached to one of the alowJy moving wheels, A» the thonBandth part of a second ia represented by an inch on the disc, we can easily under* stand that the hundredth part of an inch which is by no means difficult to measure, will represent the hundred thousandth part of a second. Experiments with this instrument, which is quite new, iwere carried on for some weeks before Christ, mas, and will be resumed again in the Spring. It- is the invention of Captain Noble, late Royal Artillery, at present one of the firm of Sir William Armstrong and Co, I

A good story is told of a clergytnnn, who, having received a public document, which was ordered to be read in all the churches, and which was particularly obnoxious to the people, shrewdly told his Congregation that though he had positive orders to read the declaration, they had none to hear it-ptbey might, therefore, leave the church. 'They 'fook the hint, and the clergyman read the document to empty pewg.