alledihe hour glass,belongs to thewater-clock classand the sa n dHows from onebulb into theother, but it givesno subdivisions ofits period, so ifyou are using oneFig. 9—Modern Sand running au houT Glass or Hour Glass •, , * , it does not giveynu the half hour.The sand glass is still in use by…
Time · Clocks and watches
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.