If you require any work done, from stone carving to digging, you seldom or never deal with the actual workman.

If you are a farmer and want your harvest got in, you contract months beforehand with an agent, who agrees to supply you with harvest- men in certain numbers, at a certain price, out of which price he pockets as large a percentage as he can, and has probably commissions to pay himself to some sub-contractor.

If you are a sculptor and wish a block of marble chiselled in the rough, the man you contract with to hew the block at certain day-wages brings a boy to do the work at half the above amount or less, and only looks in from time to time to see how the work is proceeding.

It is the same in every branch of trade or business.

If you wish to make a purchase, or effect a sale, or hire a servant, you have a whole series of commissions or brokerages to pay before you come into contact with the principal.
If you inquire why this system is not broken through, why the employer does not deal directly with his workmen, you are told that the custom of the country is against any other method; that amongst the workmen themselves there is so much terrorism and intimidation and _espionnage_, that any single employer or labourer, who contracted for work independently, would run a risk of annoyance or actual injury; of having, for example, his block of marble split "by a slip of the hand," or his tools destroyed, or a knife stuck into him as he went home at night, and, more than all, that, without the supervision of the actual overseer, your workmen would cheat you right and left, no matter what wages you paid.
After all it is better to be cheated by one man than by a dozen, and being at Rome you must do as the Romans do.
It may possibly have been observed that, in the foregoing paragraph, I have spoken of the "workmen at Rome," not of the Roman workmen.