Hines, J.
James Jones, a bojr nine years of age, was offered as a witness for the State. Counsel for the defendant objected to this witness being permitted to testify, on the ground that he was incompetent, because of his infancy. After the witness had been examined as to his competency, the court overruled the objection to his being allowed to testify, and in overruling the objection stated that “the jury passes on all of that,” and then addressed the jury as follows: “You have heard the witness examined. He was examined in your presence, in order that you *295might observe his manner and hear his statement. It is for you to pass on the question of the credit you will give his testimony, whether he understands the nature and consequences of his testimony.” To this proceeding the defendant excepted upon the ground that it was the duty of the court to pass upon the competency of this witness, and that the court erred in submitting to the jury the question whether or not the witness was competent. The competency of a witness must be. decided by the court, and the court must, by examination, pass upon the capacity of a witness alleged to be incompetent'from childhood. Civil Code (1910), §§ 5856, 5865; Moore v. State, 79 Ga. 498 (5 S. E. 51); Hicks v. State, 105 Ga. 627 (31 S. E. 579); Reece v. State, 155 Ga. 350 (116 S. E. 631). It is generally error for the court to submit to the jury the question of the competency of a witness. Hicks v. State, Reece v. State, supra. In overruling, after examinátion, the objection to the witness on the ground that he was incompetent to testify, the court necessarily held and ruled that the witness was competent, and properly submitted tr the jury the credit to be given to his testimony. The court passes upon the competency of a witness, but the jury passes upon his credibility. Hicks v. State, supra; Reece v. State, supra. While the language, “the jury passes on all of that,” used by the court after overruling the objection to the competency of the witness, standing alone, might be susceptible of the construction that the court left to the jury the determination of the competency of this witness, the charge of the court, in immediate connection with the use of such language, that it was for the jury to pass upon the credit which they would give to his testimony, renders that construction untenable. But if the court had submitted to the jury the competency of this witness, such -charge would have been more favorable to the defendant than he was entitled to, and it furnishes no ground for the grant of a new trial. Reece v. State, supra.
Children who do not understand the nature of an oath are incompetent witnesses; but it is left to the sound discretion of tne trial judge to determine whether or not a boy nine years of age is a competent witness, and where the court examines a boy of that age as to his understanding of the nature of an oath, and decides that he is competent to testify, this court will not grant a new trial where it does not appear that the discretion of the court *296lias been manifestly abused, which does not appear in this case. The competency of a child must, from its very nature, be left almost exclusively to the judge of the trial court. Peterson v. State, 47 Ga. 524. In Minton v. State, 99 Ga. 254 (25 S. E. 626), a child eight years old, who, on a preliminary examination had for the purpose of testing his competency as a witness, stated that he did not know what an oath was, was held competent. In Young v. State, 125 Ga. 584 (54 S. E. 82), a child twelve years of age, who on such examination testified that he did not know the nature of an oath, that he did not know what it was to take the Bible in his hands and swear in the case, and did not know what the sanctity of an oath was, was permitted to testify: In the present case the evidence of this child in the record, including his frank admissions of ignorance, was intelligent, lucid, consistent, and to the point; and it could be considered by the lower court in determining his competency as a witness. Moore v. State, supra. Under these decisions, the trial judge did not abuse his discretion in holding this witness competent, although the witness testified that he did not know what an oath was, nor what the truth was, and that he had never heard anything about the devil or God, or anything of that kind. Reece v. State, supra.
One Parks, a witness in behalf of the defendant, had testified that on the night of the shooting he was at his place of business at 52 Elliott' street, approximately 75 to 100 feet from the point at which the shooting occurred; that he heard four shots; that one shot was fired, and then, after an interval, three more shots were fired'in rapid succession. In an attempt to rebut this testimony, one Dabney, a witness for the State, was permitted to testify that he stationed himself at Parks’ place of business; that a pistol similar to that with which the deceased was killed, and loaded with the same cartridges, was fired five times at the point where the homicide was committed; that he heard a number of reports that sounded as though they were at quite a distance and seemed rather dim and muflied to him; that when asked by Baker, “Were those shots?” he replied that they were. Baker, a witness for the State, and the one referred to in the above testimony of Dabney, was permitted to testify that he was at Parks’ place at the time referred to by Dabney; that he knew some shots were going to be fired; that he was waiting to hear them, and that he *297heard them, but the sound was muffled. To this testimony the defendant objected, upon the ground that it was irrelevant and immaterial; that whether the test was a fair one would depend upon the surrounding conditions, whether the atmospheric and other conditions were the same on the two nights in question, and whether the same kind of weapon and powder were used on the two occasions. The court overruled these objections and permitted the witness to testify as above. To this ruling the defendant excepted. Evidence of experiments made under similar conditions and directly illustrating a material issue in the case may be given; but if the experiments were made under different conditions, or under such circumstances that they might be worthless or misleading, the evidence should be rejected. Hicks v. State, 146 Ga. 221 (91 S. E. 57). The admission of testimony as to experiments must largely rest in the discretion of the trial judge; and the exercise of this discretion will not be controlled unless manifestly abused. The weight to be attached to such testimony is for the jury, and varies according to the circumstances of similarity that the jury may find to exist between the experiments made and the actual occurrence whose facts are under investigation. Augusta Railway &c. Co. v. Arthur, 3 Ga. App. 513 (60 S. E. 213). As it does not appear that the experiments were made under circumstances different from those surrounding the occurrence under investigation, and as such evidence tends rather to support .than to refute the testimony offered by the defendant, the admission of such experimental evidence does not require the grant of a new trial:
The verdict is supported by the evidence.
Judgment affirmed.
All the Justices concur.