Lawrence (Thomas) Autograph letter signed ("Thom. Lawrence")

The letter, to an unknown recipient, reads "It is an immense vexation to me to be obliged to postpone Lady Georgiana's sitting but at the time of present appointment for it, I am obliged to attend a meeting of the Trustees of the British Museum on an urgent occasion when absence would have great appearance of impropriety" and asks to rearrange the sitting for the upcoming Thursday, two pages, some creasing and discolouration, Russell Square, 10 March 1826.