An engineer is likely to say things such as, "Particulates of iron-oxide residue." A contractor, when asked to explain this same natural occurrence, will say, simply, "rust." Engineers subscribe to the Charles Dickens School of Writing, believing that the volume of their words will signify the value of their work. Contractors talk like the folks on Jerry Springer.

Engineers wear rumpled suits. Contractors wear chinos and open-collar shirts, except for when they go to Atlantic City or Las Vegas. When at those place they will add gold chains to their chinos and open-collar shirts. This also applies to females in both professions, of course.

If Madonna pulled up to a stop light next to a male engineer, rolled down her window and gave the guy a smile you could pour on a pancake, the engineer would ask her how many cubic inches her car's engine had. A male contractor, under the same circumstances, would be rifling through his glove compartment, looking for gold chains.

An engineer will often have letters after his name on his business cards - BS, MS, Ph.D., PE, and whatnot. A contractor will look at these letters and decide that this particular engineer has absolutely no knowledge of the real world. The more letters there are, the stronger the contractor's conviction will be.

An engineer will hang his many diplomas over his desk. A contractor will hang a photograph of the Little League team his company sponsored last summer and feel just as proud.

An engineer will often look around a boiler room, desperately trying to find the boiler, which he or she perceives to be a small, square, blue box with the block-letters, BOILER, written across it. A contractor will sometimes hold the blueprints upside-down and, not realizing they are indeed upside-down, proceed to install the boiler on the ceiling. Hey, what the engineer wants, the engineer gets!

At lunch, engineers will order ice tea. Contractors will order beer.

Engineers carry Palm Pilots containing the phone numbers, addresses, and other vital statistics of everyone they've ever met in their entire lives. They will spend years tapping this information into that thin box. Contractors have the same information, but they keep it on hundreds of Post-It notes stuck to the visors and dashboards of their trucks. Big mechanical contractors don't bother with any of this information because they're not going to call you back anyway.

Engineers wear those watches with the calculators built into them. They tap at them nonstop with the tips of their Cross pens and pencils. Contractors wear Rolexes and flash them in your face as much as possible.

Engineers watch A&E. Contractors watch ESPN.

Engineers and contractors both stare at the architects, wondering what the heck is going on in their wacky heads.

Engineers and contractors both love traditional design methods, but for different reasons. Engineers love traditional methods because it means they can just keep using the standard specifications they've had in their file cabinets since 1955. Contractors love tradition because it means they don't have to take time from their busy schedule to learn anything new. When it comes to hydronic-system design, both groups believe that 1955 was a very good year!

Engineers think manufacturers reps are good guys because the reps give the engineers free catalogs filled with color pictures of the latest products, not that the engineers are planning to do anything with those catalogs. They just think the catalogs look cool up there on the shelf! Contractors also think manufacturers reps are wonderful because reps so easy to abuse.