Why was Japan so low in the maps of the seventies/eighties?

I have an atlas from the sixties and Japan is depicted low in the map down to the right in the bottom. I know this is a Mercator projection but I've seen it from the fifties/sixties seventies eighties and they still depicted it so. I mean the Mercator projection does not make Japan s location far to the right but I mean in the bottom. The same for Australia why it is depicted so low why the map was a Mercator projection?