Eiffel

A frequently cited example of protection from atmospheric corrosion is the Eiffel Tower. The narrow and, for that age, thin sections required a good priming of red lead for protection against corrosion. The top coat was linseed oil with white lead, and later coatings of ochre, iron oxide, and micaceous iron oxide were added. Since its constmction the coating has been renewed several times [29]. Modern atmospheric corrosion protection uses quick-drying nitrocellulose, synthetic resins, and reaction resins (two-component mixes). The chemist Leo Baekeland discovered the synthetic material named after him, Bakelite, in 1907. Three years later the first synthetic resin (phenol formaldehyde) proved itself in a protective paint. A new materials era had dawned. 

Valencia Parc Technologic, Calle Gustave Eiffel, 4,... 

The long thin loaves of French bread are regarded in the rest of the world as an icon of France, alongside the Eiffel Tower. Their origin is said to be that one of the Austrian queens of France demanded the sort of loaf that she was accustomed to in Vienna. Possible candidates for the queen would be Anne of Austria, wife of Louis XIII, or Marie Antoinette, wife of Louis XVI. As central European wheat is hard, resembling North American wheat, this is a formidable problem with only French soft wheat available. A modern bakery technologist would find this difficult. 

So there is a class layer of design described entirely in terms of classes, with related types, which can be implemented directly in a language such as Java, Eiffel, or C++ or otherwise by judicious application of class-to-nonclass patterns (see Figure 3.32). 

Type The designer should know what types of object can be held in a variable—that is, the expected behavior of the object to which it refers. In Self and bare Smalltalk, this is left to the design documentation in C++, Java, and Eiffel, it is exphcit and some aspects are checked by the compiler. Explicit typing is allowed in some research variants of Smalltalk because it makes it possible to compile more-efficient code other compilers try to deduce types by analyzing the code. 

Containment In Smalltalk, Eiffel, and Java, all variables contain references to other objects—implicit pointers that enable objects to be shared and allow the uses of an object to be decoupled from its size and the details of its internal declaration. In C++, some variables are explicit pointers, and others contain complete objects. The latter arrangement yields faster code but no polymorphism f)that is, one class is tied to using one specific other. This is not a generic design. In general, we consider containment to be a special and less usual case. 

Within this book, we assume that variables are typed, that access can be controlled at the package level, and that variables contain implicit references—in other words, the scheme followed by Java, Eiffel, and others. 

Eiffel is among the few programming languages to provide directly for operation specs, but they can, of course, be documented with an operation in any language. In C++, suitable macros can be used Java could use methods introduced on the superclass Object. For debugging, pre- and postconditions can be executed. 

Operation specs can be used as the basis of a test harness they can be incorporated into the code in such a way that an exception is raised if any of them ever evaluates to false. (Eiffel supports pre- and postconditions directly the standard C++ library includes an assert macro.)... 

In Java, you d think spec types would be written as interfaces. Unfortunately, if we want to put the invariants and postconditions into the types themselves in real executable form, they must be classes. This has the uncomfortable effect of disallowing one implementation class from playing more than one role. An alternative is to put all the test apparatus in a separate set of classes that interrogates the states of the types. Again, we find ourselves applauding Eiffel, in which all this is natural and easy.)... 

A class defines an implementation or partial implementation of an object, with program code for localized actions and variables for storage of its state. A class can also be documented with invariants over its variables and pre/post specifications for each operation signature. Some programming languages support these features—notably Eiffel, which provides a testing facility that uses them. 

The height of the Eiffel Tower is 986 feet. A replica of the tower made to scale is 4 inches tall. What is the scale of the replica to the real tower ... 

Figure 4.1 Eiffel Tower model built from small Meccano pieces.

Germany (IUTA/LANUV) Styrum (ub), Eiffel (rb) PM10 April-September 2008... 

Figure 2-20. Examples in architecture (a) Eiffel Tower, Paris, from below (b) Cupola of the Parliament building in Budapest (c) Pentagon in Washington, DC (photographs by the authors).

Gustave Eiffel, the French engineer who designed the ingenious support structure, knew from experience that if the copper touched the iron framework, the more active iron would corrode very rapidly. 

Whatever the mechanism, Eiffel attempted to combat the corrosion problem by inserting asbestos pads between the copper sheets and the frame. However, this idea did not work, probably because copper is such a good conductor that any contact between the two metals anywhere on the statue... 

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