“An affidavit of defense should set forth fully and fairly, facts sufficient to show prima facie a good defense, and if it fails to do so, either from omission of essential facts, or manifest evasion in the mode of statement, it will be insufficient to prevent judgment:” Sprissler v. McFetridge, 37 Pa. Superior Ct. 607. This well settled principle is applicable to the present case, as is clearly shown by the opinion of the learned judge of the common pleas.

1. Presumably, in the absence of averment to the contrary, it was within the power of the defendant to specify the number, dates and weights of the deliveries of coal that he alleges he weighed. Failing to do this, his affidavit is fatally defective so far as it sets up a defense as to any particular deliveries.

2. It is apparent that the averment that all of the deliveries mentioned in the statement of claim were short in *304weight an average of 705 pounds to the ton, is a mere inference drawn by the defendant from the average shortage that he alleges he found in the unspecified number of deliveries that he weighed. ' But the discrepancies discovered might have been so few in number and so far separated in time as to be wholly insufficient to warrant the inference asserted. In order to determine whether there was sufficient ground for probable inference that the same average shortage of weight extended over thirty-three separate deliveries that was found in the deliveries that were weighed, the number and dates of such deliveries should have been specified, being matters peculiarly within the defendant's knowledge. The facts that ought to have been stated with certainty are not so stated, and therefore the court was right in adjudging the affidavit insufficient.

The judgment is affirmed.