PPSC Past Paper Labour Inspector(BS-14) 2019 Solved MCQs, Everyday Science MCQs, PPSC Solved Past Papers MCQsWho invented Chronometer? Posted on April 17, 2021 by Rana TahirA. John Harrison B. Edison C. Michael Beats D. Calvin SmithShare this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on WhatsApp (Opens in new window)Click to share on Pinterest (Opens in new window)Click to share on LinkedIn (Opens in new window)