Complex sentence: It has been stated that the rule was tested in experiments made on Salisbury Plain in 1897, and also by experiments made by Italian naval officers on behalf of the Royal Italian Navy in 1900 and 1901.
Split into simpler sentences: It has been stated that the rule was tested in experiments made on Salisbury Plain in 1897. Also by experiments made by Italian naval officers on behalf of the Royal Italian Navy in 1900 and 1901.