Rock (geology) arkoses (12%). Sedimentary rocks often contain fossils. Sedimentary rocks form under the influence of gravity and typically are deposited in horizontal or near horizontal layers or strata and may be referred to as stratified rocks. A small fraction of sedimentary rocks deposited on steep slopes will show cross bedding where one layer stops abruptly along an interface where another layer eroded the first as it was laid atop the first. Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was
An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction Furthermore, Thomson, Jöns Jakob Berzelius, and Antoine César Becquerel observed that electricity could be indefinitely generated by friction. No educated scientist of the time was willing to hold that electricity was not a fluid. Ultimately, Rumford's claim of the "inexhaustible" supply of heat was a reckless extrapolation from the study. Charles Haldat made some penetrating criticisms of the reproducibility of Rumford's results and it is possible to see the whole experiment as somewhat tendentious. However, the experiment inspired the work of James Prescott Joule in the 1840s. Joule's more exact measurements were pivotal in establishing the kinetic theory at the