![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/f/fd/Ballpoint-pen-parts.jpg/640px-Ballpoint-pen-parts.jpg&w=640&q=50)
Calamus sphaeralis
From Wikipedia, the free encyclopedia
Calamus sphaeralis,[1] sive calamus atramentarius,[2] sive sphaerigraphum,[1][3] sive stilus sphaeratus,[4] est stilus qui atramentum per globulum capiti stili infixum in chartam aliamve materiam premit. Linea a calamo sphaerali facta, aliter atque linea stili plumbati, gummi deletili non eradi potest. Atramentum adhibitissimum est caerulei ultramarini simile, sed etiam calami atramenti aliorum colorum conficiuntur.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fd/Ballpoint-pen-parts.jpg/640px-Ballpoint-pen-parts.jpg)
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/7/70/Ballpointpentip_lessnoise.jpg/640px-Ballpointpentip_lessnoise.jpg)
László Bíró diurnarius Hungarus, qui in expositione mundana Budapestini anno 1931 habitā stilum novi generis proposuit, inventor calami sphaeralis habetur.