‘Exchange in now a pervasive presence; someone drops some money; the cashew nut seller makes a sale; I even hear the word itself dinheiro.

The street condenses around this single crude and all-embracing element. This stretch of the Avenida Celso Garcia spurns the notion that transactions and exchange take place at one remove from the pavement’s surge and flow, as all kinds of portions and parcels get levered by its dynamic, impinged on, appropriated, transformed into a floating framework wresting profit.

Its forms and guises overwhelm – the truly mobile vendor with a bulging sports-bag, the strategy of approach and veiled confrontation, or the opportunistic occupation of alcoves and other non-space geometries, but principally itinerant and on the move. A suitcase now, on wheels, or boxes strapped to sack-trucks or a trolley; an innovative manipulation of materials – convey and display – vehicle, counter, storage, all in one. These ambulantes – mobile street sellers, hone a sensitivity to street-life’s fertile flows, they know its rhythms and durations and they index favoured places. Move on, the conventional barraca – market stall, more rooted and consistent, entrenched in part by social bonds with regulars; but once again wheels and folding parts intimate a transience and mobility forced on them by the city’s timed constraints. On again, the Banca de Journal – newspaper kiosk; of plain geometry, a diversionary beacon, a node of news and information drawing retired men and taxi drivers; a detached and colourful way-marker plotted at strategic intervals along the street and its many corners. And finally, shops themselves; lacking windows and facades, their contents also garnish the street with goods and commodities, the grammar of browse and barter, of buy and sell, of purchase and exchange.

This mediating mode’s relentless; it’s gratuitous, unavoidable and everywhere; an obscene candour comes at me, roughs-up my attention, then passes by, renews itself again. I resent it, repulsed, this realisation’s raw with desperation &ndash sell, make money – it envelops me like a noxious substance I struggle to digest. It’s a dependence, an utter reliance – we’re all chained and bound by its destructive force, so why my indignation on the victims, they’re not responsible, this isn’t wilful complicity by another name. Hard though to distance yourself from reality when someone’s literally ‘in-your-face’, pestering and pushy – buy this, buy that. .  .  .