|A modern day panoramic view of The Royal Crescent in Bath (my photo)|
On September 18, 1777, Hester, the Countess of Chatham, wrote to Mrs. Pitt regarding her daughter Lady Harriot's trip to stay with her uncle (Hester's brother, Henry Grenville) at his newly built residence, number 13 Bath Crescent:
“It was only this morning that they left us, in order to set out on their Journey to morrow to look at the new House they have there, which is the best in the Crescent.” Immediately before this journey, Henry Grenville, his wife, and her niece Louisa had been staying with Lord and Lady Chatham at Hayes Place.  Lady Harriot clearly got on very well with her cousin Louisa Grenville, and they seemed to be good friends.
By Tuesday, Oct 25th 1777, the Countess of Chatham was writing to Mrs. Pitt once again as
Mr. and Mrs. Pitt were joining Lady Harriot and the Grenville’s at Bath:
“The delight of the Bath Journey will be much increas’d by the fortunate circumstance of your and Mr Pitt being to be there; and Harriot rejoices beforehand in the thoughts of your kindness to her, which she has the pleasure to know how to Judge of by experience. Pitt [John, Lady Harriot's older brother] is also to be of the Party, and I am sure from every reason he cannot feel less happy on the occasion, but will claim his right to it. At present he is following the Fox Hounds, for the first day this season.” 
It appears that Lord Pitt retained his fondness for hunting and shooting throughout his life, and it was evidently a recreation that began in his youth.
Lady Chatham was hoping that Mrs. Pitt would supervise Lady Harriot, as she had reservations about the raucous life at Bath. Nevertheless, she was pleased about Lady Harriot's friendship with Louisa:
“…Bath is not the Place in the World I like the best for Young People, but there was no refusing so kind an offer, and a Friendship between Louisa and Harriot is so natural and right, that it is to be wish’d. Louisa seems really to be a very fine Young Woman, and is certainly exceedingly accomplish’d…[it] reconciles us to the hazarding our Girl at such a Distance.” 
Louisa was Henry Grenville's only daughter, and was very close to Lady Harriot. In a previous post about Number 13 Bath Crescent, I mentioned the connection of the property to the Pitt and Grenville families, as well as Lady Harriot and Lord Pitt's [John, afterwards known as the 2nd Lord Chatham] time there in 1777. Louisa Grenville later married Charles, the 3rd Earl Stanhope, after the death of his first wife, Lady Harriot's older sister Hester, Lady Mahon, due to complications arising from childbirth.
1. Hester, Countess of Chatham to Mrs. Pitt. September 18th, 1777. Dropmore Papers, British Library Add Ms 59490, ff. 59-60.
2. Hester, Countess of Chatham to Mrs. Pitt. October 25th, 1777. Dropmore Papers, British Library Add Ms 59490, ff. 61-62.