Abstract: A hologram viewing apparatus, an integral direct viewing hologram device and an article useful in the manufacture of hologram devices are predicated upon a particular set of components grouped according to a number of permutations. The viewing apparatus comprises a screen consisting of at least a plane grating, the hologram device comprises a venetian blind film having a hologram embossed on or bonded onto one surface and a plane grating embossed on or bonded onto the other surface, and the article useful in the manufacture of hologram devices comprises a venetian blind film embossed on one side with a plane grating.

Abstract: An integral direct viewing hologram device and an article useful in the manufacture of hologram devices are predicated upon a particular set of components grouped according to a number of permutations. The hologram device comprises a venetian blind film having a hologram embossed on or bonded onto one surface and a plane grating embossed on or bonded onto the other surface, and the article useful in the manufacture of hologram devices comprises a venetian blind film with a plane grating embossed or bonded on one side.

Abstract: A mobile grain auger on a wheeled frame has a reaction member positioned to engage the ground between the axis of the wheels and the intake end of the auger casing, and a tilt adjustment mechanism connected between the reaction member and the frame to vary the inclination of the casing to the ground.

Abstract: The invention concerns the concentration or recovery of gold or silver from cyanide liquors containing either or both of them by contacting the liquors with activated carbon in order to load it with Au(CN).sub.2.sup.- or Ag(CN).sub.2.sup.- according to the particular isotherm, removing the loaded carbon and treating it with hydronium or metal cations or molecular complexes in order to convert the Au(CN).sub.2.sup.- and Ag(CN).sub.2.sup.- to insoluble AuCN or AgCN and then recycling the thus treated carbon to contact further liquor, whereby the loading of the activated carbon is far in excess of that possible by conventional reversible loading and recovery of such precious metals by converting them to reversibly loaded AuCN and AgCN which desorb down to their limits set by their respective equilibrium adsorption isotherms.

Abstract: A road testing apparatus has a framework extending over a test portion of road pavement and has tracks with upwardly curved ends along which wheels of a trolley unit roll so that the trolley unit decelerates as it approaches an end position to cause kinetic energy to be transformed into potential energy and when return motion trolley commences the potential energy transforms back to kinetic energy. The trolley unit has a pivotally mounted base structure carrying a test load and a pair of road wheels which are mounted so as to be steered by the trolley as it progresses in a forward direction along the test pavement, additional wheels of the trolley running up an end portion of the track to lift the road wheels off the road surface as the end position is reached.