Question: what powered the original locomotives on mount washington cog railway
[{'answer': 'steam engines', 'provenance': [{'wikipedia_id': '379369', 'title': 'Mount Washington Cog Railway', 'start_paragraph_id': 7, 'start_character': 304, 'end_paragraph_id': 7, 'end_character': 317, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '379369', 'title': 'Mount Washington Cog Railway', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 702, 'bleu_score': 0.9815648442794911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3236865540388567770}, 'section': 'Section::::History.\n'}]}]