I stepped from Plank to Plank — Life Insurance

I stepped from Plank to Plank 1
A slow and cautious way
The Stars about my Head I felt
About my Feet the Sea.

I knew not but the next 5
Would be my final inch-
This gave me that precarious Gait
Some call Experience.
(F.926/J.875)
[1] Plank to Plank:: items of a life insurance contract.
[2] slow and cautious:: how she was filling the contract.
[3] Stars:: fortune, fate.
[4] my Feet the Sea:: the straying feeling of her fate.
[5] next:: the next item to check, question to answer in the contract.
[6] final inch:: the last item of the contract.
[7] This gave me:: after the last item finished, the contract gave her. precarious Gait:: the manner (of walking, living) depending on unknown events.
[8] Experience:: experience table, a table of mortality computed from the experience of one or more life-assurance companies (OED 9, 1879); the term was used already in 1847.

The most important of there experiences are the Northampton table, the Charlisle table, and what we shall call the adjusted experience table, being one formed by the actuaries of the principal assurance offices in London from the experience of the duration of lives assured in their various offices. ─ The Calcutta Review (1847)