This section is from the book "The Gardener V2", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
About the middle of July Mr Speed kindly forwarded us fifteen varieties of Plums from the Plum-house at Chatsworth, his object being to show which varieties are best suited for forcing. The fruits were all from trees planted out and treated alike in the same house.
Rivers's Early Plum had been fit for use since the end of June, and the specimen of it was quite shrivelled. The next earliest was the Czar, and it was just fit for gathering, but nothing more. Belgian Purple, Goliath, Blue Prolific, and an unnamed variety, were just beginning to get a little soft. Kirk's Seedling, Jefferson, Greengage, Transparent Gage, Victoria, Angelina Burdett, Guthrie's Late, Belle de Septembre, and Golden Drop, were all hard and green. This collection made it very manifest that Rivers's Early is by far the most useful of the lot for early forcing, and the Czar succeeds it closely. It will also be very apparent how useful a Plum-house must be when planted with such a collection as the above; for from the period Early Rivers is in season, to the time when such as Coe's Golden Drop comes into use, is a very long one. Considering how very useful a fruit the Plum is, and how much it is improved by being grown under glass, it is rather surprising that Plum-houses are not more plentiful, especially in localities where the crop of fine Plums is a precarious one.
We received at the same time a sample of a seedling Tomato raised by Mr Speed, which for size and flavour surpassed anything we had previously seen. It was nearly a pound weight, and Mr Speed says it is as remarkable for its free bearing, and suitability for early forcing, as for its size and quality. It cannot fail to be an esteemed variety, now that Tomatoes have so well-deservedly become a popular vegetable.