it is asking to explain one way that scholarly disciples not recorded in history have contributed the perspectives explained by Diamond. (who im presuming is the author)
An entire suit of field armor (that is, armor for battle) usually weighs between 45 and 55 lbs. (20 to 25 kg), with the helmet weighing between 4 and 8 lbs. (2 to 4 kg)—less than the full equipment of a fireman with oxygen gear, or what most modern soldiers have carried into battle since the nineteenth century.
Castle Clinton was previously known<span> as </span><span>Castle Garden. </span>