Due to timelessness and universality of letter writing, extant letters from before eras represent a very important group of source material in historiography (the methodology of historians). Value of letters while in the 18th century[edit] Envelopes are available in plain kinds and also sorts with to some degree bigger privateness https://ali-ibn-abi-talib09873.blogsidea.com/32167666/an-unbiased-view-of-nahjul-balagha-ali-as-sayings