Damage apprehended by the appellants from breach was an indirect damage. Got their price from the respondents for each article sold, does not matter to them directly what the respondents did with it. Accordingly, the agreement is headed "Price Maintenance Agreement," and the way in which the appellants would be damaged if prices were cut is clearly explained in evidence by Mr. Baisley. But though damage as a whole from such a practice would be certain, yet damage from any one sale would be impossible to forecast. Quite reasonable for parties to contract that they should estimate that damage, and provided that figure is not extravagant there would seem no reason to suspect that it is not truly a bargain to assess damages, but rather a penalty to be held in terrorem.