Analysis of information sources in references of the Wikipedia article "منساخ" in Arabic language version.
The Pantograph has no defect in its geometrical prinicples, but, considered as an instrument for practice, it is by no means perfect. It is composed of metallic bars, which turn on five centres ; it is supported on six rollers turning also on centres, and continually changing their direction while they move along the paper ; and when the instrument is used, the force which changes its figure is in some positions applied obliquely, and thus acts at a disadvantage. In the summer of the year 1821, my attention was directed to copying instruments. I found that the Pantograph was then the only one used, and I formed the resolution of attempting to invent a new instrument, which should be free from its imperfections. … The Eidograph has been shewn (sic) to every ingenious person who has visited me since 1821,
The Pantograph has no defect in its geometrical prinicples, but, considered as an instrument for practice, it is by no means perfect. It is composed of metallic bars, which turn on five centres ; it is supported on six rollers turning also on centres, and continually changing their direction while they move along the paper ; and when the instrument is used, the force which changes its figure is in some positions applied obliquely, and thus acts at a disadvantage. In the summer of the year 1821, my attention was directed to copying instruments. I found that the Pantograph was then the only one used, and I formed the resolution of attempting to invent a new instrument, which should be free from its imperfections. … The Eidograph has been shewn (sic) to every ingenious person who has visited me since 1821,
