In Salt river and Gila valleys in Arizona the grapes are said to ripen much earlier than in California, but so far the vineyards there are not old enough to have been greatly benefited by this early ripening. On the plains of Kern county the ripening is hastened by the nature of the soil, and possibly also by the nearness to the desert and the desert wind, by the greater distance from the sea, and by a less amount of rainfall. In Malaga the grapes ripen several weeks earlier than in Fresno; in fact, the whole Mediterranean region seems to be earlier than California. As a general rule, we may state that the Muscat grapes ripen later in Southern California than in the central portion of the State. In regard to Sacramento and San Joaquin valleys, the farther we go towards the south the earlier do the grapes ripen. But in every district there are localities which are earlier than others. The Muscat and Muscatel ripen earlier than the Sultana, which latter grape begins to ripen earlier than the Muscat, but attains perfection much later than any other of our raisin grapes. Thompson Seedless ripens in Yolo about August 10th, and is thus our earliest raisin grape. _Signs of Maturity._--There are three different ways by which the ripeness of a grape can be tested,--saccharometer, taste or color. The saccharometer is a well-known instrument, consisting of a graded glass tube that will sink to different depths in liquors containing different percentages of sugar. There are different kinds of saccharometers, but the most practical one for the general raisin-grower is one divided in one hundred degrees, each degree showing one per cent of sugar to every hundred of water. Thus, if the saccharometer sinks down to twenty-five, we know that the water or must contains twenty-five per cent of saccharine water and seventy-five per cent of water. To properly test the grapes, a few bunches should be picked from several vines, the juice should be squeezed out and passed through a towel or otherwise strained. The must is then poured into the test tube, and the saccharometer inserted. If it shows twenty-five degrees or more of sugar, the grapes will make good raisins, but for very superior raisins several degrees more of saccharine are needed. It is not unusual to find the grapes reach thirty degrees in favored localities and in favorable seasons. Only inexperienced vineyardists will require the aid of the saccharometer to determine the state of ripening of the grapes; the more experienced judge by taste and color. The taste of course is the most commonly used method for ascertaining the ripeness of the raisin grapes. Every grower experienced or not should examine his grapes repeatedly. To give directions for tasting the ripeness of the grapes is of course impossible; it must be learned, and can only be learned by practice. It is enough to say here that the grapes should taste very sweet, contain no acid, and if possible be rather solid.