Roger Fischer suggests, on the basis of finds at Saqqara, that the reed pen might well have been used for writing on parchment as long ago as the First Dynasty, or around 3000 BC. Reed pens continued to be used until the Middle Ages, but were slowly replaced by quills from about the 7th century. The reed pen, made from reed or bamboo, is still used in some parts of Pakistan by young students and is used to write on small wooden boards. The reed pen survived until papyrus was replaced as a writing surface by animal skins, vellum and parchment. The smoother surface of skin allowed finer, smaller writing with a quill pen, derived from the flight feather. The quill pen was used in Qumran, Judea to write some of the Dead Sea Scrolls, which date back to around 100 BC. The scrolls were written in Hebrew dialects with bird feathers or quills. There is a specific reference to quills in the writings of St. Isidore of Seville in the 7th century. Quill pens were still widely used in the eighteenth century, and were used to write and sign the Constitution of the United States in 1787. A copper nib was found in the ruins of Pompeii, showing that metal nibs were used in the year 79. There is also a reference to 'a silver pen to carry ink in', in Samuel Pepys' diary for August 1663. 'New invented' metal pens are advertised in The Times in 1792. A metal pen point was patented in 1803, but the patent was not commercially exploited. A patent for the manufacture of metal pens was advertised for sale by Bryan Donkin in 1811. John Mitchell of Birmingham started to mass-produce pens with metal nibs in 1822, and after that, the quality of steel nibs improved enough so that dip pens with metal nibs came into general use. The earliest historical record of a pen with a reservoir dates back to the 10th century AD. In 953, Ma'ād al-Mu'izz, the Fatimid Caliph of Egypt, demanded a pen which would not stain his hands or clothes, and was provided with a pen which held ink in a reservoir and delivered it to the nib. This pen may have been a fountain pen, but its mechanism remains unknown, and only one record mentioning it has been found. A later reservoir pen was developed in 1636.