I bought a copy of their sons birth certificate. Details are 4th October 1848, Francis, boy, father-John James Francis Chevalley, mother-Louisa Cheavalley formerly Frampton, fathers occupation-cook, Informant-Louisa Cheavalley,mother (the address given is either King Street or High Street, Wimborne.
Chevalley is often mis-spelt as Cheavalley and the father was born Jean Francois Chevalley in Switzerland but anglicised his name. I have also seen him listed as Francis and John.