in somerville's time the value of scientific publications depended on the currency of the information, therefore frequent editions had to be produced. her subsequent books reflect the time she could free in her domestic life as her children became more independent but also the need to earn money, as the somervilles had a number of financial crises that peaked in 1835. as a middle-class woman she publicly and plausibly maintained that she wrote only for pleasure. privately she paid considerable attention to the profitability of her books. through personal connections she could secure john murray as the publisher of her first book "mechanism", and he remained her publisher throughout her long career. murray later commented that despite him having made little profit he was very pleased to have had the honour of publishing the works of such an extraordinary person. her second book "on the connexion of the physical sciences" sold 15,000 copies and established her reputation in elite science.