In August, as dealers abandon salerooms for the south of France, auctioneers try to lure private collectors with pop and transport memorabilia and marine paintings. And big fairs offer days out for the family.

The 4,050 stands of the world's biggest fair - at Newark, Nottinghamshire, on Tuesday - will offer goods totalling pounds 50m and attract up to 15,000 people. The six annual Newark fairs are breeding grounds for collecting trends. The markets for old Bakelite radios, fountain pens and novelty biscuit tins were first spotted at Newark.

It is an international fair with Americans, Dutch and Germans highly visible. Watch the Italian wholesalers marking the pieces they have bought with prices before putting them aboard container lorries.

Latest trends? For what it's worth, West Coast American decorator types are snapping up those wartime vacuum cleaners with a slim dust cylinder on the shaft. They are also buying wheel trims - car hub caps to us. How long before the first hub cap auction in Britain? The fair is at the Newark and Notts Showground, near the A46 junction to Lincoln. About 1,800 of the stands are under cover and there is free parking. Entry is pounds 3 (accompanied under-16 year olds free) or pounds 20 on Monday, the day before opening, when traders are setting up and circulating the choicest pieces among themselves. Further information: IACF (01636-702326).

Other fairs: The four-day NEC August Fair in Birmingham, with 600 dealers, continues today and tomorrow (0121-767 2760). Newmarket Antique and Collectors Fair, Sunday 18 August at Rowley Mile Racecourse, where members of the international Oughtred Society will be scouring stands for what is, to them, the hottest collectable - historic slide rules.

Ballooning as a hobby has made balloon and Zeppelin ephemera eminently collectable. Prices have been rising steadily since last year, when a Zeppelin coffee cup and saucer with authentic "LZ" monogram, estimated pounds 300-pounds 500 at Christie's South Kensington, fetched more than pounds 1,500. Much of the Zeppelin bric-a-brac in South Ken's sale, Thursday 15 August (10.30am), was either nicked as souvenirs by passengers or jubilant Brits during the first world war after the giant German airships had been shot down. Sometimes the twisted metal was fashioned into souvenirs: lot 299, estimated at a conservative pounds 250-pounds 300 in the sale, comprises a dozen or so bits and pieces including a brooch depicting a Zeppelin made from wreckage of the L15 downed in the Thames estuary in 1916. A dessert plate and a matching tea plate from the Hindenburg, which exploded in 1937, putting paid to the Zeppelins' career, is estimated pounds 800-pounds 1,200.

Stock clearance! Bonhams made a virtue of offering art dealers' dead stock last year in a "tag" - that is, price tag - sale with no bidding. The knocked-down pictures and sculpture walked out, as they say. This year's sale, next Saturday and Sunday, offers over 400 pieces priced between pounds 100 and pounds 3,000.

Bonhams' summer rock and pop sale, Thursday 22 August (12 noon), offers possessions of Jimi Hendrix preserved by Kathy Etchingham, who shared his flat between 1968 and 1969. The Oriental prayer rugs, beads and velvet cushions all have four-figure estimates. His black laquer and mother of pearl inlaid stash box is estimated pounds 4,000-pounds 5,000.

Among the 100 historic machines from the world's first Tricycle Museum at Christchurch, near Bournemouth, offered for sale at Phillips in Retford next Saturday (10.30am) is a unique Victorian "Rantoone" tricycle propelled by all four limbs, the only surviving example of its kind. Some 10 million people have visited the museum since its foundation ten years ago by collector- curator Roger Street, a local solicitor. But he could no longer cover its costs and Christchurch Council refused to rescue it.

The Rantoone, patented in 1863 and known as the "gymnasium in miniature" is estimated pounds 15,000-pounds 20,000 Enthusiasts with less money to spend can pick up a between-wars trike in the sale for pounds 250 or so. A steam-assisted child's tricycle is estimated pounds 350-pounds 500.