From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

One of the earliest modes of representing visibly the words or ideas already orally expressed. For many centuries the key to these representations was altogether unknown; but a piece of granite found near Rosetta by the French army in 1798, and now in the British Museum, contains a decree in honour of Ptolemy Epiphanes (204 B.C.) written in hieroglyphics with a Greek translation alongside. Also the shaft of an obelisk brought to England from Philae in the S. of Egypt contains a hieroglyphic inscription of its dedication to the gods by Ptolemy Physcon and Cleopatra (146 B.C.) and at the base a Greek inscription. Champollion, by comparing the Greek names Ptolemy and Cleopatra with the hieroglyphics corresponding, made out letter by letter.

Young and others have perfected the transcription of Hebrew and the Egyptian hieroglyphic. Thus the derivation from Egyptian of many of the Hebraized words in Exodus is proved, confirming its having been written by one in such circumstances as Moses was. The hieroglyphics originally were picture writing, but in the form handed down to us on oldest monuments they are phonetic with occasionally an accompanying picture of the object in order to make the group of hieroglyphic letters which form the word more intelligible. Thus to the names of individuals the figure of a man is attached; such characters called "determinatives". The initial of the Egyptian ( Αhom) for eagle is "A"), so an eagle became the representative of "A" ( 'Αleph ( א )); a lion (Egyptian Labo ) is "L" ( Lamed[H] ( ל )); an owl ( Μowlad ), "M" ( Μem (Final) ( ם )).

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

Bibliography Information McClintock, John. Strong, James. Entry for 'Hieroglyphics'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. https://www.studylight.org/encyclopedias/eng/tce/h/hieroglyphics.html. Harper & Brothers. New York. 1870.