Pointsman: A man who has charge of the points* on a railway.  The term was later occasionally employed to refer to a signalman. (e.g. bar565 Only a Pointsman)

* A pair of tapering movable rails forming a junction at which railway vehicles are directed from one set of rails to another; the junction as a whole [OED].

A pair of tapering movable rails forming a junction at which railway vehicles are directed from one set of rails to another; the junction as a whole [OED]

Poor Richard's Almanack was a yearly almanac published by Benjamin Franklin, who adopted the pseudonym of "Poor Richard" or "Richard Saunders" for this purpose. Franklin included proverbial sentences about industry and frugality.
http://en.wikipedia.org/wiki/Poor_Richard's_Almanack

The Poor Law Reform Act of 1834 was designed reduce the cost of supporting the unemployed and poverty-stricken, by forcing those seeking help apply to workhouses where they would be made to undertake manual labour.  Previously such people had been supported by grants - ' outdoor relief' as opposed to incarceration -  raised through parish poor rates that were levied on the local property owners.  This new was regarded by its supporters more efficient and cheaper.

Reference:
Bates, Stephen - Two Nations: Britain in 1846. (London,  Head of Zeus, 2015) p54

A children's singing game. The children form several rings, in each ring one child stands he or she is the weasel the children dance round and sing the song, as the last line is reached (Pop goes the weasel) all the children rush to a new ring, the last child to join the ring is eliminated, until only one child is left. Pop goes the weasel.
https://history.knoji.com/pop-goes-the-weasel-and-other-playground-singing-games/

Pawn brokers shop

 Originally ginger beer or champagne, later an effervescent or carbonated drink [OED]

Porter : A dark-brown or black bitter beer, brewed from malt partly charred or browned by drying at a high tem-perature. [OED]

A case or bag for carrying clothing and other belongings when travelling; (originally) one of a form suitable for carrying on horseback (OED)

A case or bag for carrying clothing and other belongings when travelling; (originally) one of a form suitable for carrying on horseback [OED]

Post boy: The postilion of a stagecoach, post-chaise, or hired carriage, [OED]

A post rider. One of a relay of riders delivering the Royal Mail

To travel in the manner of a post-rider, i.e with relays of horses [OED]

Street vendor of hot potatoes

A pot, tankard, or similar container, (usually) spec.one having the capacity of a pottle
or
A unit of capacity used chiefly for liquids (but also for corn and other dry goods, and rarely for butter), equal to half a gallon (approx. 2.3 litres). [OED]

meaning not known

meaning not known

A small compter, or prison, run by a Sheriff of the City of London from medieval times until 1815. [Wikipedia]  

Before 1974 1 pound (£) sterling = 20 shillings; 1 shilling = 12 old pennies
UK currency was 'decimalised' in 1974

1 pound weight = approx 0.454 kg