"The Green Meadow" by H.P. Lovecraft and Winifred V. Jackson

Both authors used pseudonyms, with "Elizabeth Neville Berkeley" being Jackson and "Lewis Theobald, Jun." being Lovecraft. Although Lovecraft actually wrote the entire text, but Jackson is credited since it was based on a dream she had experienced.

360 lbs = 163 kg
5 x 3 inches = 12.7 x 7.6 cm

To follow along: https://www.hplovecraft.com/writings/texts/fiction/gm.aspx