A scarce mathematical treatise aimed at teaching trigonometry to an increasingly globalised audience. The first part concerns the doctrine of spherical trigonometry, and the second applies it to the measurement of altitude, distance, fortification, and most extensively navigation. Thereafter follow sections applying spherical trig to practice in geographical and astronomical problems, as well as arithmetical and instrumental dialling. A significant portion of the work focuses on the calculation of longitude.
The navigational problems use geographical examples which hint at the increased importance of transoceanic travel in the mindset of the eighteenth century. These include Penguin Island, Port Royal, Barbados and Cape Verde, often using Lizard in Cornwall as the starting point for the problem. With the first Longitude Act passed by British parliament in 1714, the quest to master a method of reliable calculation became something of a national pastime, and books like this would have been invaluable manuals in this task.
William Hawney was a schoolmaster and mathematician best known for his Complete Measurer which went through at least eighteen English language editions. The present work is much rarer, and was, according to the preface, published just after Hawney's death.
Ownership inscription to front free endpaper of Rebecca Craven Wymondham, 1817.
Rare Book Hub finds only three copies in auction records. ESTC, T113396.
