Pontoon bridge in 638. The army of the Umayyad Caliphate built a pontoon bridge over the Bosporus in 717 during the Siege of Constantinople (717–718). The Carolingian army of Charlemagne constructed a portable pontoon bridge of anchored boats bound together and used it to cross the Danube during campaigns against the Avar Khaganate in the 790s. Charlemagne's army built two fortified pontoon bridges across the Elbe in 789 during a campaign against the Slavic Veleti. The German army of Otto the Great employed three pontoon bridges, made from pre-fabricated materials, to rapidly cross the Recknitz river at the Battle on the Raxa
Junk fax Junk fax Junk faxes are a form of telemarketing where unsolicited advertisements are sent via fax transmission. Junk faxes are the faxed equivalent of spam or junk mail. Proponents of this advertising medium often use the terms "broadcast fax" or "fax advertising" to avoid the negative connotation of the term "junk fax". Junk faxes are generally considered to be a nuisance since they waste toner, ink and paper in fax machines. Junk faxing came into widespread use in the late 1980s as a result of the development and proliferation of relatively inexpensive desktop fax machines which resulted in rapid growth