just like a goldsmith banker

正如金匠银行家那样
--he leaves only enough gold in the safe

他留存在保险箱中的黄金数量
to cover the kind of withdrawals that are normally accepted.

刚好可以应付一般的提款要求
In that case, the bank can pay interest to depositors.

这样银行就可以向存款人支付利息了
Even though the deposits are short-term

即使是短期存款
and the depositor can get the money at any time,

存款人可以随时取走存款
the depositor is earning interest of a level

存款人也可获取仅从长期贷款中
that can only be made on long-term loans.

才可得到的利息水平
People can't pay --they can't pay a high interest

如果银行不发放长期贷款
if they don't have it as a long-term loan.

他们就不能够支付高额利息
Now incidentally,

顺便说一下
often bank loans to corporations are short-term, technically,

技术上讲银行借给公司的都是短期贷款