The magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty (since about 206 BC), and later adopted for navigation by the Song Dynasty Chinese during the 11th century. The first usage of a compass recorded in Western Europe and Persia occurred around the early 13th century.
The highest monthly average temperature in Athol for July is 71 degrees. The lowest monthly average temperature in Athol for December is 26 degrees. The most monthly precipitation in Athol occurs in January with 1.7 inches. The air quality index in Athol is 21% better than the national average. The pollution index in Athol is 91% better than the national average.
Concrete should not be exposed to temperatures 20ÂºF above the minimum placement temperatures. ACI 306R-88 Chpt 7.4 11. The temperature of the concrete and the ambient air and recorded at least twice in 24 hr period. Temperatures should be taken at more than one location, on edges and corners. 12. mix. APWA 03 30 04 2.5 E1 4. Non chloride admixtures may be used but placement, curing and protection requirements must be observed. APWA 03 30 10 3.4 A2 5. Temperature of concrete as placed should be as close to the minimum recommended value as possible (55Âº F) ACI 306R-88 Chpt 3.1 6.