The events leading up to the statement made by the eight witnesses is not covered in the Times and Seasons record. However, Lucy Mack Smith, the mother of Joseph Smith, Jr. gave a small amount of insight in the paragraph below which comes from Chapter 31 of her record  in the paragraph below referencing the day after the three witnesses obtained their view of the plates by an angelic manifestation:
The following day, we returned a cheerful, happy company. In a few days, we were followed by Joseph, Oliver, and the Whitmers, who came to make us a visit, and make some arrangements about getting the book printed. Soon after they came, all the male part of the company, with my husband, Samuel and Hyrum, retired to a place where the family were in the habit of offering up their secret devotions to God. They went to this place, because it had been revealed to Joseph that the plates would be carried thither by one of the ancient Nephites. Here it was, that those eight witnesses, whose names are recorded in the Book of Mormon, looked upon them and handled them. Of which they bear record in the following words (see below from the Times and Seasons account).
This is a continuation of the History of the Church by Joseph Smith as recorded in the Times and Seasons in 1842.
Soon after these things had transpired, the following additional testimony was obtained:–
AND ALSO THE TESTIMONY OF EIGHT WITNESSES.
Be it known unto all nations, kindreds, tongues, and people, unto whom this work shall come, that Joseph Smith, Jr. the translator of this work, has shewn unto us the plates of which hath been spoken, which have the appearance of gold; and as many of the leaves as the said Smith has translated, we did handle with our hands: and we also saw the engravings thereon, all of which has the appearance of ancient work, and of curious workmanship. And this we bear record with words of soberness, that the said Smith has shewn unto us, for we have seen and hefted, and know of a surety, that the said Smith has got the plates of which we have spoken. And we give our names unto the world to witness unto the world that which we have seen; and we lie not, God bearing witness of it.
PETER WHITMER, JR.,
JOSEPH SMITH, Sen.,
SAMUEL H. SMITH
 The Prophet and His Progenitors for Many Generations, Published for Orson Pratt by S. W. Richards, Liverpool, 1853 – https://contentdm.lib.byu.edu/digital/collection/NCMP1820-1846/id/16386