Monthly payments from the buyer should add up to something nearer the full value of the property-assuming the seller dies at the time suggested by actuarial tables.

买方每月的付款总额应该接近房产的全部价值——假设卖方在精算表推测的时间死亡。

He invented the weather map and actuarial table, proposed methods for working out the age of the Earth and its distance from the Sun, even devised a practical method for keeping fish fresh out of season.

他发明了气象图和运算表，提出了测算地球的年龄和地球到太阳的距离的方法，甚至发明了一种把鱼类保鲜到淡季的实用方法。