science

Lapis manalis

Lapis manalis is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Lapis manalis rather than just read about it. In short: A lapis manalis was either of two sacred stones used in the Roman religion. Although they had the same name, they were distinct stones: one the cover to the gate of the underworld and the other a rainmaking stone.

Key takeaways

Lapis manalis belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Lapis manalis to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Lapis manalis from memory before moving on to harder problems.

Reference excerpt

A lapis manalis was either of two sacred stones used in the Roman religion. Although they had the same name, they were distinct stones: one the cover to the gate of the underworld and the other a rainmaking stone.

Gate to the underworld

One lapis manalis covered the mundus Cereris, a pit thought to contain an entrance to the underworld. The grammarian Festus called it ostium Orci, "the gate of Orcus". Most cities of Latium and Etruria contained a similar pit or ditch; Plutarch describes the custom of a mundus as being of Etruscan origin, and states that it was used as a place where first-fruits were deposited. The Latin word mundus meant "world". Festus, quoting Cato this time, explains that:

Mundo nomen impositum est ab eo mundo qui supra nos est.

(The mundus gets its name from that world which is above us.) The Roman mundus was located in the Comitium. This stone was ceremonially opened three times a year, during which spirits of the blessed dead (the Manes) were able to commune with the living. The three days upon which the mundus was opened were August 24, October 5, and November 8. Fruits of the harvest were offered to the dead at this time. Macrobius, quoting Varro, says of these days that:

Mundus cum patet, deorum tristium atque inferum quasi ianua patet.

(When the mundus is open, it is as if a door stands open for the sorrowful gods of the underworld.) Accordingly, he reports that military and public matters were not transacted upon them, even though they were not dies nefasti.

Charm to make rain The other lapis was used as part of a ceremony called the aquaelicium (Latin: "calling the waters") which sought to produce rain in times of drought. During the ceremony, the pontifices had the stone brought from its usual resting place, the Temple of Mars in Clivo near the Porta Capena, into the Senate. Offerings were made to Jupiter petitioning for rain, and water was ceremonially poured over the stone. The name of this stone may have been derived from the verb manare, "to flow".

See also Lemuria, another Roman festival for the dead. Lemures, hostile ghosts in Roman mythology.

References

Worked examples

Example 1 — a first encounter with Lapis manalis

Start with the simplest possible case. Write down what Lapis manalis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Lapis manalis before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Lapis manalis ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Lapis manalis

In research: Lapis manalis appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Lapis manalis in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Lapis manalis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ancient Roman religion, Rainmaking (ritual), Roman underworld, so understanding it makes those chapters shorter.
In everyday life: Look for Lapis manalis outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Lapis manalis in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lapis manalis means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Lapis manalis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lapis manalis in simple terms?

Why does Lapis manalis matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Lapis manalis?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Lapis manalis.