Add spaces: Theburnersaremadeofbrass,anespeciallyrobustandhigh-qualitymaterialforlongyearsofcontinualuseacrossawiderangeofpowersettingsupto6,000watts.

Answer: The burners are made of brass, an especially robust and high-quality material for long years of continual use across a wide range of power settings up to 6,000 watts.

Add spaces: Cookat800Wfor4minutespereach100g(ie8minutesfor200g).

Answer: Cook at 800 W for 4 minutes per each 100 g (ie 8 minutes for 200 g).

Add spaces: ThebookwasbasedonalecturecoursehehadgivenatYaleUniversityintheUnitedStates.

Answer:
The book was based on a lecture course he had given at Yale University in the United States.