As a rule it may be said that, where the rainfall is sufficient to grow the Muscats without irrigation and cause them to bear good crops, the fall rains are also too frequent and too injurious to the drying grapes to allow a profitable raisin cult. The proper amount of moisture necessary to perfect the grapes cannot be ascertained by the aid of the rain gauge. While, as we have said, from twenty to thirty inches may be enough in Smyrna, from seven to ten inches suffice in El Cajon, and in Chile even less is required. The proper amount of moisture can best be told by the state of growth of the vines. The vines must have moisture enough to be kept growing up to the very time of the maturity of the grapes. The proper sign of this is the green and fresh color of the young shoots or the tips, combined with a certain vigor of the tendrils. When the tips cease to grow, and the tendrils begin to dry up, then the moisture has begun to give out, and irrigation should have been resorted to; the winter rains were not sufficient. _Frosts in Spring and Winter._--One of the frequent effects of spring showers is spring frosts. They are always injurious to the tender Muscat vine, and if occurring more than once during the same spring may entirely ruin the crop. In California such frosts occur sometimes in April, and observations inform us that they are most to be feared between the tenth and fifteenth of that month, while sometimes they come even later. The young buds are then either opening or fully developed into shoots, which the lightest frost will blacken and cause to dry up. Where the vines are irrigated and strong, one such frost may not ruin the crop, as new buds will start out in place of the old ones destroyed, and new shoots and new blossoms will come out. I have seen as many as three such crops of shoots develop from the winter buds, but each succeeding crop of such shoots is weaker than the preceding one, and bears less and later grapes. Happily, these frosts occur but very seldom in the Central and Southern California raisin districts, and during fifteen years of observation I have seen only three such frost years in which the branches were partially injured. In neither of these seasons was the crop materially injured as to quantity, the principal effect of the frost being a retarding of the crop for a week or more. Smoking of vineyards can only be successfully carried out in small valleys sheltered from heavy winds, but on the open plains such smoking is accompanied with difficulties, and its effect is uncertain. The growing of a limited number of windbreaks has in the Fresno district no doubt modified the climate, and made spring frosts rarer and less to be feared.