Letter, from Giovanni Antonio Plana to Sir John Herschel, dated at Turin Autograph letter signed by sender, with annotations by recipient. Responds to receipt of sample impression of Giovanni Plana's memoir [see Giovanni Plana's 1825-12-3]. Comments on printing and paying arrangements, and to whom copies are to be sent. Comments on value of using an equatorial telescope as opposed to a meridian circle. [Some parts of the letter are illegible.] 18 January 1826