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Numb. 47.
PHILOSOPHICAL
TRANSACTIONS.
May 10. 1669.
The Contents.
Instructions concerning the Use of Pendulum-Watches for finding the Longitude at Sea; together with a Method of a Journal for such Watches. An extract of a Letter written from Vienna concerning two Mock-Suns lately seen in Hungary. A Relation of the Conferences held in the Royal Parisian Academy for the Improvement of the Arts of Painting and Sculpture. An Account of some Books. I INSTITUTIONUM CHRONOLOGICARUM Libri duo, una cum totidem ARITHMETICES CHRONOLOGICÆ Libellis, per Guil. Beveregium M. A. II. ELEMENTS OF SPEECH; An Essay of Inquiry into the Natural Production of Letters together with an Appendix of a Method to instruct Persons Deaf and Dumb; by William Holder D. D. &c. III. GUAGING PROMOTED, begin an Appendix to Stereometrical Propositions formerly publish't by Rob. Anderson.
Instructions
Concerning the Use of Pendulum-Watches, for finding the Longitude at Sea.
WHereas 'tis generally esteemed that there is no Practise for the Finding of the Longitude at sea comparable to that of those Watches, which instead of a Ballance-wheele are regulated by a Pendulum, as now they are brought to great perfection, and made to measure time very equally; and many perhaps here as
well
