Abstract: A catalyst of a phosphoric acid treated carrier formed from clay minerals and silica gel for the hydration of a C.sub.2-3 olefin to an alcohol is prepared by acid treating an essentially montmorillonite-containing clay contaminated with not more than 3% of extraneous materials until an acid treated clay is obtained having a 10-20% by weight Al.sub.2 O.sub.3 content and a specific surface area of 200 to 400 m.sup.2 /g, adding from 20 to 40 parts by weight of finely particulate silica gel having a particle size distribution of between 30 and 60.times.10.sup.-6 m, a pore volume of 0.9 to 1.7 ml/g and a specific surface are of 200 to 500 m.sup.2 /g and from 1.5 to 2.5 parts by weight of titanium dioxide, each based on total dry substance, to said acid treated clay, shaping the acid treated material to a total water content of 40 to 60% by compression, calcining the shaped material at 500.degree. to 900.degree. C., in a second stage, acid treating the calcined material with acid until it has an Al.sub.2 O.sub.

Abstract: An artificial hand having at least one finger and a thumb is provided with drive motor and a gear to open and close the finger and thumb. A gear wheel is secured to each joint where the finger and thumb is connected to the hand proper. A motor driven worm gear meshes with both gear wheels and reversible gears are interposed between the motor and the worm gear, whereby an axially displaceable shaft maintains the interconnection between the drive means and the worm gear.