Page 26. " being made commander in consequence of the action off St. Domingo "

Santo Domingo, the founding city on the island Columbus named Hispaniola, changed hands quite a few times in the early 19th century. 

 

Hispaniola 1671
Public DomainHispaniola 1671 - Credit: wikimedia commons

It was a city integral to colonial interests in the West Indies and a destination of great value to pirates and buccaneers.  When Austen's Captain Wentworth joined battle there (c. 1806) it was in French hands. 

 Santo Domingo is now part of the Dominican Republic.

Page 38. " to which the present daughters of the house were gradually giving the proper air of confusion by a grand piano forte and a harp, flower-stands and little tables placed in every direction. "

Accomplished young ladies in the Regency period were expected to excel at music, specifically the piano forte (or fortepiano).

Pianoforte and harp
Creative Commons Attribution Share AlikePianoforte and harp - Credit: Thesupermat

While this picture depicts a far grander salon (Le Petit Trianon), the Musgroves would have been able to afford very good instruments and the character of Louisa suggests she would have demanded them.

Fortepiano 1805
Creative Commons Attribution Share AlikeFortepiano 1805 - Credit: Paul McNulty, Viviana Sofronitzki

The sound quality differed on the piano forte, an early version of a piano.  The octave range also was smaller.

Here is an example of an early 19th century song for the piano such as the misses Musgrove might have learned to play:

 

Page 39. " who had brought from a school at Exeter all the usual stock of accomplishments "
Exeter
Creative Commons AttributionExeter - Credit: Oliver Beige

Exeter lies on the river Exe in Devon. The 'usual stock' of  accomplishments would have included sewing, dancing, and deportment. Being taught how to be a lady was considered to be of more importance than the more academic subjects.

 

 

Page 41. " none of your Queen-squares for us! "

 

Engraving of Queen Square
Public DomainEngraving of Queen Square

Queen Square is an elegant Palladian square in the centre of Bath. Built by the architect John Wood the Elder, Queen Square was one of the first Georgian developments in the city. By Austen's day, it was associated with the old Establishment; the Musgrove girls would prefer to be in a newer, and consequently more fashionable, part of town.

 

Page 45. " Anne, very much preferring the office of musician to a more active post, played country dances "
Country Dancing
Public DomainCountry Dancing - Credit: T. Wilson

Anne plays country dances on the pianoforte; music that was meant to accompany a structured, but animated form of dancing exercise and entertainment. Precise placement of feet and hands was essential. 

Country Dancing 2
Public DomainCountry Dancing 2 - Credit: T. Wilson