22 – The Province of Massachusetts Bay sends 2,000 troops to supplement other British Army and colonial forces in Acadia; the troops anchor at Chignecto Bay on June 1. May 24 – France completes the construction of Fort Duquesne, its new base to the west of the British colony of Pennsylvania. The British capture the fort during the French and Indian War and rename it Fort Pitt. The site, at the junction of the Allegheny River and the Monongahela River, is now Pittsburgh. May 30 – General Braddock's troops begin a difficult trek across the heavily wooded Allegheny Mountains from western Maryland into the Ohio country. June 5 Scottish chemist Joseph Black describes his discovery of carbon dioxide (fixed air) and magnesium, in a paper to the Medical Society of Edinburgh. The paper is published in 1756 with the title Experiments upon Magnesia alba, Quicklime, and some other alkaline Substances. At the entrance of the Saint Lawrence River, a squadron of Royal Navy ships, under the command of British Admiral Edward Boscawen, intercepts the nine French ships dispatched to save Canada; seven of the nine ships are concealed by fog and are able to reach their destination; another of the transports escapes. June 16 – After a two-week siege, the French commander of Fort Beauséjour in North America surrenders to the British, marking the end of "Father Le Loutre's War". June 23 – Most of the French troops dispatched to Canada arrive at Quebec, along with the new Governor General of New France, Pierre de Rigaud, Marquis de Vaudreuil-Cavagnial. June 27 – Iyoas I becomes the new Emperor of Ethiopia upon the death of his father, Iyasu II July–September July 9 – French and Indian War – Braddock Expedition: British troops and colonial militiamen are ambushed and suffer a devastating defeat inflicted by French and Indian forces. During the battle, British General Edward Braddock is mortally wounded. Colonel George Washington survives. July 17 – In a convoy of ships from Great Britain, returning to India for the East India Company, the lead ship Doddington (on her third voyage) wrecks in Algoa Bay near modern-day Port Elizabeth in South Africa, losing 247 of its 270 passengers and crew, together with a chest of gold coins from Robert Clive worth £33,000. In 1998, 1,400 coins from the wreck site are offered for sale, and in 2002 a portion is given to the