In this letter the English astronomer answers to Secchi (Fig. 1-2), who had communicated to him the outcome of his observations, noting that the comparison between the photographs he obtained and the ones of De La Rue showed a perfect agreement of the results. De La Rue finds this agreement interesting, because it brang to an end the question of the solar nature of the protuberances; He informs him of the results of other expeditions and announces that he will write them again, to send him copy on glass of his photographs. Indeed, De la Rue went then to Rome in person to compare his photographs with those of Secchi, confirming the agreement of the results obtained.
