YOU SAID:
The greatest invention from the past 250 years is the steam engine
INTO JAPANESE
過去250年間の最大の発明は蒸気機関である
BACK INTO ENGLISH
The greatest invention of the last 250 years is the steam engine
INTO JAPANESE
過去250年間の最大の発明は蒸気機関である
BACK INTO ENGLISH
The greatest invention of the last 250 years is the steam engine
That didn't even make that much sense in English.