Though not designed by Froebel, this marble mosaic set feels very Froebel-ian, designed to encourage design learning and creative play. I've found a few other antique "Mosaik" or "Mosaic" sets with clay marbles, including sets made by Richter (Meteor) and, later, Milton Bradley, but no other made by Samuel Gabriel Sons & Co., NYC, which Harvard cites as having been founded in 1907, selling paper novelties and publishing children's books, until being bought by American Colortype in the 1930s. I believe this set, which appears fairly complete (and perhaps having acquired a few slightly larger clay marbles over time) dates to the very early years of the company. I especially love the slogan on the front of the box: "to keep busy the little hands and little head."
Box measures 15 1/16" x 12" x 2. Overall very good condition, with general wear to the paper label on the box and to the marbles. Box is very structurally sound with no losses, and a hook on the front that latches tight. The marble board inside is wooden and of nice quality (most sets one sees feature cardboard board.) More marbles could certainly be incorporated.