TABLE 7.5. CENTRAL FUNCTIONS TYPICAL OF LEVELS IN THE HIERARCHY OF CENTRAL PLACES, SOUTHWESTERN IOWA, 1960

<table><thead><tr><th>Level</th><th>Function</th></tr></thead><tbody><tr><td>(A) The Village-level functions</td><td></td></tr><tr><td>Gas and service station</td><td>Meeting hall</td></tr><tr><td>Automobile repair</td><td>Hardware</td></tr><tr><td>Bars</td><td>Farm materials</td></tr><tr><td>Restaurants</td><td>Farm sales</td></tr><tr><td>Grocery</td><td>Farm implements</td></tr><tr><td>Post Office</td><td>Oil fuel bulk station</td></tr><tr><td>Local government facility</td><td>Barber</td></tr><tr><td>Church</td><td>Beauty shops</td></tr><tr><td>(B) The Town-level functions</td><td></td></tr><tr><td>Furniture</td><td>Doctors</td></tr><tr><td>Appliances</td><td>Dentists</td></tr><tr><td>Variety</td><td>Building services</td></tr><tr><td>General clothing</td><td>Building materials</td></tr><tr><td>Drugstores</td><td>Radio-TV sales and service</td></tr><tr><td>Banks</td><td>Movers and haulers</td></tr><tr><td>Insurance agents</td><td>Funeral home</td></tr><tr><td>Real estate</td><td>Veterinarian</td></tr><tr><td>Telephone exchange</td><td>Automobile accessories</td></tr><tr><td>Cleaners</td><td>Farmers' cooperatives</td></tr><tr><td>(C) The City-level functions</td><td></td></tr><tr><td>Women's clothing</td><td>Newspaper publisher</td></tr><tr><td>Men's clothing</td><td>Office of labor union</td></tr><tr><td>Shoes</td><td>Sales of new automobiles</td></tr><tr><td>Jewelry</td><td>Sales of used automobiles</td></tr><tr><td>Florist</td><td>Specialized automobile repairs</td></tr><tr><td>Supermarket</td><td>Automobile wrecking</td></tr><tr><td>Bakery</td><td>Cleaners and laundry (operator)</td></tr><tr><td>Liquor store</td><td>Self-service laundry</td></tr><tr><td>Other medical practice (e.g. op-<br>tometrists, etc.)</td><td>Shoe repairs</td></tr><tr><td>Lawyer</td><td>Plumbing</td></tr><tr><td>Hotel</td><td>Fixit</td></tr><tr><td>Motel</td><td>Movies</td></tr><tr><td>County government</td><td>Indoor amusements (billiards, etc.)</td></tr><tr><td></td><td>Drive-in eating places</td></tr></tbody></table>

Source: Berry, Barnum, and Tennant (1962) Tables IV-VI

METHODS OF DESIGN GROWTH

GROWTH BY ACCRETION — SPACE AS CONNECTOR

This is a method used by Greek designers with
superlative skill. Each new building, internally or-
dered around one axis, is so placed in relation to
existing buildings that an angular volume of space
is created which binds the two together. Coherence
is maintained by the tension between buildings
across the angular space. The elegance and beauty
of the spaces created, as here in Camiros, and the
endless variety of interrelationships between the
internally disciplined buildings provide a principle
for city design applicable to problems today.

AXES AS CONNECTORS

When the Greek sensitivity gave way to the
Roman love of order and logic, a new element was
introduced in large-scale design, that of interlock-
ing axes. Thus the five "new" fora of Rome, built
one after the other by emperors, lie next to one
another, with little or no space between. The
central axis of each building was made exactly
perpendicular to that of the one before, producing
a system of cross axes that unified the whole. Be-
cause of their interrelationship, designs which in
themselves are very formal and perhaps rather
sterile create a dynamic over-all result.

MASS AS CONNECTOR

In the later period of the Roman Empire, no-
tably under Hadrian, a new freedom of design
crept in, a return to large-scale site-planning based
on a variety of angular relationships. The Romans
developed a far greater variety of architectural
forms than did the Greeks. Curved structures such
as exedras, rotundas, and cylindrical colonnades
offered a wide range of angular sub-axes which
could interlock various parts of the composition.
Thus, in Roman work, such as Hadrian's villa,
at left, it was curved building mass which bound
together the various parts of a many-angled com-
position.

GROWTH BY ACCRETION — INTERLOCKING
SPACES AS CONNECTORS

During the medieval period, up to the fifteenth
century, cities often grew around rectangular
spaces. These gradually took form as individual
buildings were built around their periphery. In
Todi, Italy, an extraordinary result came about
through the conception of two interlocking prisms
whose corners overlapped to create a single in-
tensive volume of space. The latter was strength-
ened and emphasized by the construction of two
tall towers which contributed a vertical force at
the point of juncture. This principle is seen in
many forms in medieval cities.

GROWTH BY TENSION

At the beginning of the Baroque period the
ordering principle in the growth of the city of
Rome was the establishment of lines of force
which defined the tension between various land-
marks in the old city. The interrelationship of
these lines and their interaction with the old struc-
tures set into play a series of design forces which
became the dominating element in the architec-
tural work along them. Here the cohesive element
is a line of force rather than a volumetric form.

GROWTH BY EXTENSION

Still a different concept is a line of force ex-
tending outward from the point of origin in the
city and establishing an ordering principle that
penetrates the adjacent land area. The Champs
Elysées in Paris dramatically illustrates this. There,
in the extension of the medievalv conceived gar-
den of the Tuileries Palace, we can trace the line
of propulsion which thrusts farther and farther
into the surrounding countryside. This first thrust
was joined by a series of similar ones which set
up a network of design systems that were capable
of indefinite extension.

While there are many other modes of city
growth, the six concepts just discussed are basic
themes which occur again and again.

<table><thead><tr><th></th><th>Beson-<br>nung</th><th>Regen</th><th>Wind</th><th>Trocken-<br>heit</th><th>Staub<br>Sand</th><th>Feuch-<br>tigkeit</th><th>Wärme</th><th>Kälte</th><th></th></tr><tr><th></th><th>Sun</th><th>Rain</th><th></th><th>Drought</th><th>Dust<br>Sand</th><th>Mois-<br>ture</th><th>Heat</th><th>Cold</th><th></th></tr></thead><tbody><tr><td>Tropenzone</td><td>+</td><td>+</td><td>○</td><td></td><td></td><td>+</td><td>+</td><td>○</td><td>Tropical zone</td></tr><tr><td>Subtropische Zone</td><td>—</td><td></td><td></td><td></td><td></td><td></td><td>—</td><td>—</td><td>Subtropical zone</td></tr><tr><td>Gemäßigte Zone</td><td>○</td><td>+</td><td>+</td><td></td><td></td><td>+</td><td>○</td><td></td><td>Temperate zone</td></tr><tr><td>Trockenzone</td><td>+</td><td>○</td><td>—</td><td>+</td><td>+</td><td>○</td><td>—</td><td>—</td><td>Dry zone</td></tr><tr><td>Monsungebiet</td><td></td><td>+</td><td>○</td><td>○</td><td></td><td>+</td><td></td><td></td><td>Monsoon area</td></tr><tr><td>Subarktische Zone</td><td>○</td><td></td><td>+</td><td></td><td></td><td></td><td>○</td><td>+</td><td>Subarctic zone</td></tr></tbody></table>