To [unidentified] 12 September 
My dear Sir
Perhaps you may remember that some months since, you were kind enough to procure for me from Mr Clark, a letter asking the Lieut. Governor at Addiscombe1 to allow me to inspect the model of St. Helena kept there.2
The publication of my geology has been much delayed, & now before going to press, I am particularly anxious to see the model once again, to correct the proportion of some geological sections.3
Would it be asking you too great a favour to take the trouble of procuring for me some note to the Governor, or resident authority for this purpose.
I should esteem it a very great favour, if you could effect this for me; & will excuse the liberty I take in troubling you.— In case you should be able procure permission for me; perhaps you would be good enough to communicate it to me by the Post.
Believe me dear Sir | Yours very truly obliged | Charles Darwin 36 Great Marlborough St.
Seeks permission to make another visit to Addiscombe [Military College] to see again the model of St Helena. He needs to correct proportion of some geological sections in his Geology [see Volcanic islands, ch. 4].