About: http://webisa.webdatacommons.org/410180745

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Instead of the refractive objective lens 70 tiltable at angle ??1 shown in FIG. 9, one may employ the toric lens 80 shown in FIG. 8 or other suitable focusing device to produce partially focused beam 125.
http://www.w3.org/ns/prov#wasQuotedFrom	google.fr