Baptist Ronchetti came to Manchester from northern Italy in about 1790 and set up a barometer business. His son Charles Joshua Ronchetti worked briefly with Vittore Zanetti and then on his own from 1816. Later, he sold optical and mathematical instruments. In about 1842, he opened a chemical works in Clayton, Manchester, leaving his sons, John Baptist and Joshua, to take over the scientific instrument business. They sold it to Joseph Casartelli in 1851, after he married their sister Harriet. and took over the chemical works after Charles Joshua emigrated to America.