Sci­ence and engi­neer­ing may be con­flat­ed to some degree in the pub­lic mind, but any­one who’s spent much time in an aca­d­e­m­ic depart­ment belong­ing to one or the oth­er of those branch­es of endeav­or knows how insis­tent­ly dis­tinc­tions can be drawn between them. Bill Ham­mack, a pro­fes­sor of engi­neer­ing at the Uni­ver­si­ty of Illi­nois Urbana-Cham­paign who’s been there since he was a mas­ter’s stu­dent in 1986, sure­ly has his own thoughts on the sub­ject. The video above from his pop­u­lar YouTube chan­nel Engi­neer­guy explains how cathe­drals were designed in the Mid­dle Ages, using the exam­ple of Sainte-Chapelle in Paris. Specif­i­cal­ly, it gets into how such a build­ing’s arch­es and sup­port­ing walls could have been engi­neered with­out the aid of sci­ence at all, or even the use of math­e­mat­ics.

Com­pared to today, the scope of knowl­edge human­i­ty com­mand­ed back in medieval times may have been impos­si­bly nar­row — to say noth­ing of the knowl­edge pos­sessed by any giv­en human, espe­cial­ly out­side the lit­er­ate elite. Yet what was then known proved more than suf­fi­cient to build struc­tures that still stand, and indeed impress, many cen­turies (and in some cas­es, more than a mil­len­ni­um) lat­er.

Ham­mack explains that, in the place of mak­ing cal­cu­la­tions, their builders would per­form actions. For instance, a medieval mason would have made a life-size chalk draw­ing of the arch, laid a rope along its form, and cut the rope’s length to match that of the arch. He could then use the rope to deter­mine just how thick the wall would need to be, between a fourth and a fifth of the arch’s span, with­out a num­ber ever being involved.

Ham­mack notes that the Romans, too, under­stood this nec­es­sary pro­por­tion for arch con­struc­tion. “The pro­por­tion­al rule does­n’t come from some sci­en­tif­ic analy­sis of stone and its prop­er­ties,” he says. “It comes from cen­turies of expe­ri­ence, from tri­al and error.” Such heuris­tics, or rules of thumb, con­sti­tute “an impre­cise method used as a short­cut to find a solu­tion to a prob­lem, often by nar­row­ing the range of pos­si­ble solu­tions.” They’re also employed in the engi­neer­ing method to “cause the best change in a poor­ly under­stood sit­u­a­tion using avail­able resources.” Its thor­ough­go­ing prac­ti­cal­i­ty would seem to have lit­tle to do with the dif­fer­ent sort of rig­ors that apply in sci­ence, where estab­lish­ing truth, or at least the absence of false­ness, is all. Belief in the engi­neer­ing approach to prob­lems like this does­n’t require faith in the reli­gious sense, but if you like, you can find proof of its effec­tive­ness in hous­es of wor­ship from Sainte-Chapelle to the Pan­theon to Hagia Sophia — or at least in their arch­es.

Relat­ed Con­tent:

Göbek­li Tepe: The 12,000-Year-Old Ruins That Rewrite the Sto­ry of Civ­i­liza­tion

The Cre­ation & Restora­tion of Notre-Dame Cathe­dral, Ani­mat­ed

An Ani­mat­ed Video Shows the Build­ing of a Medieval Bridge: 45 Years of Con­struc­tion in 3 Min­utes

Behold a 21st-Cen­tu­ry Medieval Cas­tle Being Built with Only Tools & Mate­ri­als from the Mid­dle Ages

How Design­ing Build­ings Upside-Down Rev­o­lu­tion­ized Archi­tec­ture, Mak­ing Pos­si­ble St. Paul’s Cathe­dral, Sagra­da Família & More

The Longest Con­struc­tion Projects in His­to­ry: Why Sagra­da Família, the Milan Duo­mo, Greek Tem­ples & Oth­er Famous Struc­tures Took Gen­er­a­tions to Com­plete

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. He’s the author of the newslet­ter Books on Cities as well as the books 한국 요약 금지 (No Sum­ma­riz­ing Korea) and Kore­an Newtro. Fol­low him on the social net­work for­mer­ly known as Twit­ter at @colinmarshall.

We’ve all stayed at the Chelsea Hotel, though most of us have done so only in our minds, through such cul­tur­al arti­facts as Leonard Cohen’s “Chelsea Hotel No. 2,” Bob Dylan’s “Sara,” Nico’s “Chelsea Girls,” Andy Warhol’s epony­mous film that includes the Nico song, or Pat­ti Smith’s Just Kids, which tells of the time she spent there with Robert Map­plethor­pe. Enthu­si­asts of the work of every­one from Janis Joplin to Arthur C. Clarke to Miloš For­man to Dylan Thomas to Mark Twain may not know that they, too, there­by enjoy an indi­rect con­nec­tion to that New York insti­tu­tion, which has stood on West 23rd Street since its con­struc­tion in 1884.

At that time, it also stood quite tall, loom­ing over every oth­er apart­ment build­ing in the city, and indeed over most of the rest of Man­hat­tan. Nowa­days, how­ev­er, the cul­tur­al pro­file of the Chelsea Hotel (offi­cial­ly, and less cool­ly, the Hotel Chelsea) is high­er than its phys­i­cal one ever was.

Its rep­u­ta­tion as a refuge for artists dates to the man­age­ment of Stan­ley Bard, who inher­it­ed the busi­ness from his father in 1964. Already, a degree of dilap­i­da­tion in the build­ing itself, as well as the sur­round­ing neigh­bor­hood, kept rents low enough to attract impe­cu­nious cre­ative types. Bard dis­played enough gen­eros­i­ty to artists that, before long, Andy Warhol’s fac­to­ry had more or less moved in.

The Chelsea’s lat­est trans­for­ma­tion began in the mid-two-thou­sands with a series of takeovers and ren­o­va­tions not nec­es­sar­i­ly wel­comed by the exist­ing long-term res­i­dents, who appre­ci­at­ed the hotel pre­cise­ly for its seem­ing imper­vi­ous­ness to gen­tri­fi­ca­tion. In the new Archi­tec­tur­al Digest video above, cur­rent own­er Sean MacPher­son gives a tour of the lux­u­ri­ous Chelsea of the twen­ty-twen­ties, all of whose spaces have been metic­u­lous­ly curat­ed to evoke its sto­ried past. In its bar (with cig­a­rette burns care­ful­ly pre­served) guests can order a cock­tail called the Two Dylans, named in homage to both Bob and Thomas; in the base­ment, they can choose from the largest selec­tion of Japan­ese whiskey at a new restau­rant named after for­mer res­i­dent Teruko Yokoi. The expe­ri­ence of a nine­teen-six­ties New York bohemi­an is now avail­able to all of us — or at least those of us who can come up with $500 per night.

If you want to revis­it the hotel dur­ing its pre-restora­tion hey­day, you can watch the 1981 doc­u­men­tary below. It will let you get glimpses of Andy Warhol, William S. Bur­roughs, Nico, and more.

Relat­ed con­tent:

New York’s Famous Chelsea Hotel and Its Cre­ative Res­i­dents Revis­it­ed in a 1981 Doc­u­men­tary

Vin­tage Footage Shows a Young, Unknown Pat­ti Smith & Robert Map­plethor­pe Liv­ing at the Famed Chelsea Hotel (1970)

Nico Sings “Chelsea Girls” in the Famous Chelsea Hotel

Thanks­giv­ing Menu at the Plaza Hotel in New York City (1899)

Watch Iggy Pop Per­form Dylan Thomas’ “Do Not Go Gen­tle Into That Good Night”

Archi­tect Breaks Down Five of the Most Icon­ic New York City Apart­ments

Based in Seoul, Col­in Marshall writes and broad­casts on cities, lan­guage, and cul­ture. He’s the author of the newslet­ter Books on Cities as well as the books 한국 요약 금지 (No Sum­ma­riz­ing Korea) and Kore­an Newtro. Fol­low him on the social net­work for­mer­ly known as Twit­ter at @colinmarshall.