Let us begin with the house, the central point of the economic and religious unit. The earliest Italian house was little more than a wigwam, more or less round, constructed of upright posts connected with wattles, and with a closed roof of straw or branches.[143] This would seem to have been the type of house of the immigrating people who settled on the tops of hills and lived a pastoral life; when they descended into the plains and became a settled agricultural people, they adopted a more roomy and convenient style of building, suitable for storing their grain or other products, and for the maintenance of a fire for cooking these. Whether the rectangular house, with which alone we are here concerned, was developed under Greek or Etruscan influence, or suggested independently by motives of practical convenience, is matter of dispute, and must be left to archaeologists to decide.[144] This is the house in which the Latin family lived throughout historical times, the house which we know as the sacred local habitation of divine and human beings. It consisted in its simplest form, as we all know, of a single room or hall, the atrium, with a roof open in the middle and sloping inwards to let the rain fall into a basin (_compluvium_). Here the life of the family went on, and here was the hearth (_focus_), the "natural altar of the dwelling-room of man,"[145] and the seat of Vesta, the spirit of the fire, whose aid in the cooking of the food was indispensable in the daily life of the settlers. This sacred hearth was the centre of the family worship of later times, until under Greek influence the arrangement of the house was modified;[146] and we may be certain that it was so in the simple farm life of early Latium. In front of it was the table at which the family took their meals, and on this was placed the salt-cellar (_salinum_), and the sacred salt-cake, baked even in historical times in primitive fashion by the daughters of the family, as in all periods for the State by the Vestal virgins. After the first and chief course of the mid-day meal, silence was enjoined, and an offering of a part of the cake was thrown on to the fire from a small sacrificial plate or dish (_patella_).[147] This alone is enough to prove that Vesta, the spirit of the fire, was the central point of the whole worship, the spiritual embodiment of the physical welfare of the family.