The article suggests that certain regional differences between ancient installations that served similar purposes can be explained as being the result of two distinct types of transfer: complete and conceptual. In complete transfer, newly-introduced installations are identical or almost identical to those of the place from which they were derived. In conceptual transfer, it is only the general concept that is transferred. As a result, in the recipient region a very different device develops.The article describes two cases of conceptual transfer: the lever-anddrum press in israel and the rotary hand mill in China. It then goes on to discuss a third case, screw weights in israel. This case not only helps to explain the unusual topographical distribution of the various types of weights but also demonstrates both types of transfer.