Colonization Rooms Printed Circular, November 1, 1848
The pattern
This still is filed under Scarcity close.
Define
A real limit (time, units, seats, eligibility) that makes delay cost something.
Mechanism
Loss of option. The close is the disappearing chance, not a louder adjective. Fake scarcity is a different and worse pattern.
Verdict
The limit is true
Why it works
The appeal is built as an audit rather than a plea. It opens by quoting the Society's own prior published estimate, then reconciles every figure against it, so the reader is walked through a ledger and arrives at the shortfall himself before any ask is made. The pre-emptive objection is handled head-on in the middle: the paragraph about gifts not being wasted or squandered in vain experiments answers the donor's real doubt before the burden of this appeal is named. Cost is then divided down to a single unit, $50 per emigrant, and split further by state, which converts an institutional deficit into something a few individuals in each State could personally close. Italic is used sparingly enough that the one fully italicised sentence carries the emotional turn of the whole letter.
Steal this when
Copy this when you are asking money from people who have already given and who suspect the last round was wasted: publish the arithmetic, reconcile it against what you promised last time, then reduce the gap to one unit small enough for one reader to fund alone.