English modal verbs have been the object of linguistic analysis from different perspectives. The study of modal verbs in technical texts in the domain of history, however, has not enjoyed a same interest, despite the relevant information an analysis of diaphasic variation may bring. My working hypothesis is that there is a significant use of modal verbs with a dynamic sense, as described in Palmer (2001). My interest in this work is to detect the use and function that dynamic modals have in a body of technical texts in English in history texts from the eighteenth and nineteenth centuries. This study, as already said, seeks to explore the value of dynamic modality in scientific writing that is in the texts compiled for the Corpus of History of Texts in English (CHET), subcorpus that is part of the Coruna Corpus of English Scientific Writing (1700-900). The methodology used includes the use of corpus linguistics tools for the analysis and retrieval of data. In addition to the technical means, an inspection of each of the examples obtained from CHET is necessary to accurately determine the dynamic modal value of the verbs, as well as their specific use in the contexts in which they appear. The results of this analysis are given quantitatively along with presenting a qualitative interpretation of these results. The conclusions of this study includes an account of the modal forms with modal dynamic nuances, as well as their function in the texts.