changing color of glas changes in the color of geasa are caused by subjecting it to the action of what aie known as ultraviolet ray ct light the same son roay be observed in high mountains where old glass from hot es original ly green after exposure to the light of 11 great elevation in the eglons ot i mow attains a le tint the same results may also be seen in connection with tho glass insulators used on telegraph or telephone lines in mountain ds tracts during a period of years an observer says that he has to ml it interesting to watch the changes in hue of the insulators on the telephone line connecting laggan station of the canadian pacific railway with the chalet at lake louise the elevation Is between and feet and while the line runs through the forest almost all the way the actinic effect of the light has changed the green glass of those insulators that have been up for several years to a bril llant purple those that have been in service longest apparently have the deepest tint hand tacking tool in the illustration below will be found a band tacking tool which is especially designed to be used in con with lasting machines which fold in the edge of the upper and hold it in place the tool being used to secure the folded held by the machine in devices of this character the discharge end of the tool is pressed against the work when the tack is driven it is feces sary either to have some means tor automatically conducting the bachs magazine supplies the tacks into the raceway or to have the latter filled from some outside source this method Is inconvenient and occasions loss of time and it has been ascer t lined from practical use that tools of this description are generally cumber some and inconvenient to handle in the tool chown here the magazine raceway and mechanism are all placed in a casing the tacks are automat icalla td from the magazine to the raceway which leads to a point where the tacks are driven the raceway Is kept full so long as are tacks in the magazine all possibility of the becoming clogged in the race way or at the entrance being avoided this is accomplished by closing the bottom ot the cylindrical magazine with a head which Is fitted into the magazine and connected to the driver the arrangement being such that the piston head will lift the tacks up to and deposit them on the raceway so that they may hang point down the driver Is then manipulated force be ing in this way applied to the head ot the tack and the latter driven into the last sun s size keeps it hot it Is the size of the sun that keeps it hot according to sir lodge it is not a furnace like a coal furnace kept hot by combustion that would fr not do it Is kept hot by its own r gravitation and earthquake fences it Is a great mass of gas con tr acting and being so enormous gen crates heat by its contraction the power of gravitation on the sun is so great that it would be impossible lor a man to move about lie would weight about two and a halt tons and he would just have to lie down and squashed by his own weight the bulk of the sun is a million times that of the earth and the shrinking to produce white heat need not be great A few yards a century suffices ob are being carefully record ed so that in a few centuries the blight shrinkage might be noted t f missing link again f again on the trail of the missing link two years ago certain marks were found on a block of sandstone near warrnambool in australia which were thought to bo the imprints of the footsteps of a prehistoric man A the time this idea was ridiculed but a plaster cast was sent to germany and the inevitable german savant went out to invests gate the matter he now reports that n his opinion they were genuine hu man imprints and this taken in con junction with the extraordinary hu man to be seen in the war museum Is supposed to show that a between humanity and the ape has been discovered the idea of the german doctor is that at an early day the sandstone where the imprints were found had been a great level beach on which perhaps pre historic men were accustomed to camp how gold leaf Is made by heating gold may be extended to 60 times its original surface gold leaf Is made from a small ingot of pare gold weighing two ounces this Is annealed and hammered until it la reduced to one sixth of an inch thice and Is then passed between steel rollers until it is formed into a weighing only six and a halt grains per square inch it 1 then cut up into pieces one inch square which are piled up alternately with pieces of vellum four inches square the beating 1 performed with a ac pound hamme