Question: who solved the problem of longitude at sea
[{'answer': 'John Harrison', 'provenance': [{'wikipedia_id': '16440', 'title': 'John Harrison', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 13, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '16440', 'title': 'John Harrison', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 211, 'bleu_score': 0.69865074830766, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11368509043003169948}, 'section': 'Section::::Abstract.'}]}]