This happened years and years ago. A friend back in Connecticut had neighbors who visited Hawaii and came back with some in-the-shell macadamia nuts. Martin, the husband, was an engineer who adored this sort of challenge. He built a hydraulic macadamia nut cracker. Two levers, one for coarse and the other for fine adjustment. Stroke, stroke, stroke on the coarse lever brought the piston down to the nutshell, then stroke as needed on the fine adjustment to crack the shell and free up the rich oily nut. The only problem was that macadamia nuts in the shell are unobtainable in Connecticut and the only value of Martin's contrivance was to entertain people with a demonstration. Eventually they were down to a few rancid nuts, but they could still be used to demonstrate the unique hydraulic macadamia nut cracker. My brother once told me that cashews come in clusters, surrounded by a very thick hard shell. And that every year people are killed by falling clusters of cashews in the shell. Makes my New Jersey black walnuts seem picayune. Judy