Opinion by
Mb. Justice Thompson,A court without doubt is the best interpreter of its own rules and its constructions of them ought to be authoritative. The court below made the following rule: “ All affidavits on the *139part of the plaintiff or defendant may be made either by the party or his agent, but when made by an agent, the character of such agency, and his means of knowledge of the facts alleged in his affidavit must be set forth, and also the reason why the affidavit is not made by the party himself.” The effect of this rule is involved in the compliance with it of certain persons making affidavits of defense in the present case, growing out of a contract between appellant company and the Waynesburg Natural Gas Company, one of the appellees.
The affidavits were made by J. B. F. Iiinehart et al. The original affidavit set up a defense to the action and the supplemental one was directed solely to the authority to make the affidavit in question. In the supplemental affidavit they aver that they made the original affidavit for themselves and as agents for the appellee company and that the reason for making the same is “that they are the only persons having any knowledge of the facts set forth in plaintiff’s statement, or the answers filed by them; that no answer is filed by the said Waynesburg Natural Gas Company by its corporate officers, for the reason that there are no corporate officers, of said company, as the same has been mei’ged by letters patent, issued by the commonwealth of Pennsylvania, into the Manufacturers Light and Heat Company; that no answer has been filed by the Manufacturers Light axxd Heat Compaxxy, by its corporate officers, under its corporate seal, for the reason that said company or its officers have no knowledge whatever of the matters embraced in this action or with any of the matters set out ixx plaintiff’s statement or the answer heretofore filed. That the answer is filed by these affiants at the request of the officers of the Manufacturers Light and Heat Company, for the reason that they are the only persons having any interest in the Waynesburg Natural Gas Company, at the time the contract referred to was entered into, and the only persons who could answer the matters set out in plaintiff’s statement.” They also aver that they were the owners of all the capital stock of the Waynesburg Natural Gas Company at the time the agreement sued upon was executed and are directly interested in the event of this suit. Upon the affidavit the learned judge below held that under the rule of court the affiants were competent to make the affidavit and he said: “ The affidavits in this case *140fully show upon their face the character of the agency of the affiants and that they are the only persons who have knowledge of the facts involved in the issue raised. This not only meets the requirements of our rule of court, but conforms to what Mr. Justice Paxson, in the case of Griel v. Buckius, 114 Pa. 187, states as the correct rule of law on the subject:
“ The correct rule would seem to be that when a defendant puts in a stranger’s affidavit, it must show upon its face sufficient reason why it is not made by the defendant himself; that a real disability existed which prevented him from making it and the circumstances giving rise to the disability.”
The supplemental affidavit avers that the affiants acted as the agents of the appellees and that they filed the affidavits at their request; that they were the only persons who had knowledge of the defense and that they were directly interested in the event of the suit. It therefore shows a sufficient reason for the failure of the appellees to make the affidavit; that the affiants are not interlopers and have an interest in the suit; that a legal reason is given therein by the appellees for not making the affidavit by the corporate officers and that a disability does exist. Clearly therefore the supplemental affidavit shows that affiants were competent and authorized to make the original affidavit of defense and the supplemental one. It may be said that where a party on the record is unable to make the affidavit by reason of sickness or absence, his clerk or anyone who has knowledge may make the affidavit; that a stranger who is interested in the defense of a suit may make the affidavit of defense : Sleeper v. Dougherty, 2 Wharton, 177; Hunter v. Reilly, 86 Pa. 509.
The learned trial judge was guilty of no error in discharging the rule for judgment for want of a sufficient affidavit of defense and the order discharging the rule is affirmed.