Single-walled carbon nanotubes (SWNTs) offer the prospect of both new fundamental science and useful (nano) technological applications(1). High yields (70-90%) of SWNTs close-packed in bundles can be produced by laser ablation of carbon targets(2). The electric-are technique used to generate fullerenes and multi-walled nanotubes is cheaper and easier to implement, but previously has led to only low yields of SWNTs3,4. Here we show that this technique can generate large quantities of SWNTs with similar characteristics to those obtained by laser ablation. This suggests that the (still unknown) growth mechanism for SWNTs must be independent of the details of the technique used to make them. The ready availability of large amounts of SWNTs, meanwhile, should make them much more accessible for further study.