15

Oct 3d 1880 — Filled box (inch by inch) with very fine ferruginous sand — dampened it roundquite stiff drove pencil down middle — (roofed hole with bits of grass) & put on pot to dry. —

(Oct 5 8˚a.m thoroughly dried — cannot pass pencil down — does inside contract first or these set & resist? Gave it 5 oz of water & left till after 2˚P.m more damp & then put again before fire — A very little water down pipe. —)

Oct 7th repeated process

9th do — The pen-holder will pass down both holes but not the original pencil — Do not regard mouth of burrow, for I stopped with blotting paper to prevent water flowing down.

Oct 11th Process repeated

15 do do

17th do do

19th do do

21st do do — In the mica calcareous argillaceous moss the pen-holder will not go — In the other it will go down, but hole is evidently much smaller than when made with pencil.