Abstract: Direct positive silver halide photographic light-sensitive materials are described in which at least one layer of light-sensitive silver halide photographic emulsion layers and other hydrophilic colloid layers applied on a base contains a mercapto compound represented by the following general formula (I) or (II) as a nucleating agent: ##STR1## wherein Z, L.sub.1, L.sub.2, L.sub.3, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and m are as defined in the specification. The nucleating agents can also be added to processing solutions.

Abstract: A waterproof watch case construction depends on gaskets alone for waterproofing and is free of cement. The construction is such that a broken crystal can be readily replaced, and the watch case itself can be of any shape, including square, ovoid and hexagonal, as well as circular. The watch crystal is located positively by means of a bezel and a ring which compress a gasket both axially and radially against the watch crystal.

Abstract: A watch case in which a bezel of a crystal and a case band are removably secured together by engagement of a plate spring secured to the bezel with an inclined surface of the case band. A waterproof relation can be obtained between the bezel and the case band by providing a gasket between the bezel and the case band. The plate opening has one portion secured in a recess of the bezel and a bent portion engaging the inclined surface.

Abstract: A noncircular watch case is provided which includes a case body underlying and supporting a noncircular crystal. A pin and crown arrangement is mounted in the case body and is operatively connected to the watch movement for performing a plurality of functions. Fixedly connected at its ends to the back cover of the watch is a spring member which is releasably connected to the case body interior. For releasing the case body and crystal mounted therein from its connection to the spring and back cover, the case body is provided with a lug which is fixedly mounted thereon. An upward pressure may be manually applied to the lug, while the back cover is held in fixed position for releasing the spring from its preselected setting in a groove of predetermined incline in the case body.

Abstract: A water-tight watch case in which an elastic gasket interposed between an inner case body and a glass or a glass frame formed as a part of glass is pressed, by engaging projections provided on both ends of an elastic leaf spring or an elastic bar incorporated in a groove provided on the outer periphery of said inner case body formed as a part of a back cover, into a groove provided on an outer case body formed as a part of a bezel.