3.3 Letters 10.37 and 10.90 - Letters to Emperor Trajan, Aqueducts
Pliny's Letters 10.37 and 10.90 move from private literary correspondence into official exchange with Emperor Trajan. These letters show Pliny as governor of Bithynia-Pontus, reporting on public works and provincial administration, and asking the emperor how to proceed. Both letters deal with infrastructure and civic concerns in the province, and together they illustrate the dependence of provincial governors on imperial authority.
You should connect technical Latin to Roman government, provincial administration, patronage, and the relationship between a governor and the emperor.

Historical Context
Trajan ruled from 98 to 117 CE. He expanded the empire to its greatest territorial size and oversaw extensive public building programs and the enactment of several social welfare policies. Pliny the Younger served as governor of Bithynia-Pontus — a province on the southern shore of the Black Sea (now in Turkey) — from about 110 to 113 CE, where he wrote to Trajan about local problems and decisions.
Aqueducts mattered because water supply was a public good and a visible sign of Roman order. When Pliny writes about aqueduct construction and other public works, he is also showing his role as an administrator who depends on imperial authority.
Letter-Specific Context
Letter 10.37 — Pliny to Trajan on the Aqueduct at Nicomedia
In this letter, Pliny reports to Trajan about a failed aqueduct project in the city of Nicomedia. The residents had attempted — more than once — to build an aqueduct, but the project was left unfinished and the money spent was essentially wasted (perdo — "to waste, lose, squander" — is key vocabulary here). Pliny describes how large sums were poured into construction that was then abandoned or demolished, with nothing to show for the expense.
Pliny asks Trajan for guidance on how to proceed: should a new attempt be made? He notes that the area has water available and suggests that the project is achievable, but he needs the emperor's authorization and, critically, a competent engineer or architect (architectus). The letter illustrates the dependence of provincial governors on imperial decision-making, especially for expensive public works. It also reflects Trajan's larger role in overseeing public building across the empire.
Letter 10.90 — Pliny to Trajan on the Aqueduct at Sinope
In this letter, Pliny writes to Trajan about the water supply of the city of Sinope. The residents lack clean water and must rely on sources that are neither pure nor plentiful. Pliny reports that there is a good water source available, but bringing it to the city will require the construction of an aqueduct. He notes that a previous attempt was begun but left unfinished, and he asks Trajan to authorize the project and provide the necessary resources.
Like Letter 10.37, this letter deals with the practical challenges of provincial infrastructure. Pliny presents the facts — the need for water, the availability of a source, and the cost of construction — and defers to Trajan for the final decision. The letter shows Pliny acting as a careful administrator: he identifies a civic problem, proposes a solution, and seeks imperial approval before committing funds. The parallel with the Nicomedia letter (10.37) reinforces recurring themes of wasted expenditure, the need for skilled oversight, and the limits of a governor's independent authority.
These two letters together illustrate themes of imperial oversight and public administration: Letter 10.37 centers on the failed aqueduct project at Nicomedia, while Letter 10.90 centers on the water supply at Sinope. Both show Pliny navigating the limits of his own authority and deferring to Trajan on matters of provincial infrastructure.
Brief Review Context
Pliny's relationship with Trajan is the most important social context for these letters. Pliny holds real power as governor, but he still frames major provincial decisions as matters for the emperor's approval. His deferential address (domine) and careful reporting show political patronage at the highest level: Trajan grants authority and favor, while Pliny performs loyalty and administrative competence.
In Roman society, enslaved people were legally considered property and had few legal rights. They performed manual and domestic labor, but some were highly educated and worked in roles such as bookkeeping or medicine. Many had been captured through war or piracy from across Europe and the Mediterranean. If freed through manumission, they usually became clients of their former master; they might gain Roman citizenship and even wealth or influence, although they were barred from holding political office. This background is not central to 10.37 and 10.90, but it is required review context for the Pliny unit.
Required Vocabulary
The following vocabulary is required for this topic. Pay attention to how each word functions in context within the letters.
| Vocabulary | Part of Speech | Definition |
|---|---|---|
| aetas, -atis (f.) | noun | life of a man, age, lifetime, years |
| Alexandrinus, -a, -um | adjective | Alexandrian, pertaining to Alexandria (a city in Egypt) |
| ante | preposition/adverb | (with acc.) (of space) before, in front, forwards; (of time) before, previously |
| appello (adp-), -are, -avi, -atum | verb | to call, address, name; request, implore, demand |
| architectus, -i (m.) | noun | architect; inventor, designer |
| arcus, -us (m.) | noun | bow, arc, arch; rainbow; anything arched or curved |
| autem | conjunction | but, on the other hand, on the contrary, however |
| beneficium, -i (n.) | noun | favor, benefit, service, kindness |
| civitas, -atis (f.) | noun | city, state; citizenship |
| defendo, -ere, -i, defensum | verb | to defend, guard, protect, look after; repel, ward off, prevent; support, preserve |
| dominus, -i (m.) | noun | master, possessor, ruler, lord, owner; male slave-owner |
| exercitus, -us (m.) | noun | disciplined body of men, army |
| facilis, -e | adjective | easy to do, easy, without difficulty |
| flumen, -inis (n.) | noun | a flowing, flood, stream, running water, river |
| fortasse | adverb | perhaps, possibly; it may be |
| forum, -i (n.) | noun | forum, market; the Forum (in Rome); court of justice |
| frustra | adverb | in vain; for nothing, to no purpose |
| genus, -eris (n.) | noun | race, family, birth, descent, origin, sort, kind |
| Harpocras, -tis (m.) | noun (proper) | a Greek male name |
| iatraliptes or -es, -ae (m.) | noun | doctor, especially one who uses massage and ointments |
| imperator, -oris (m.) | noun | commander, leader, chief, director, ruler, general, emperor |
| itaque | conjunction | and so, and thus, and accordingly |
| ius, iuris (n.) | noun | right, justice, duty, law |
| leo, leonis (m.) | noun | lion |
| liberta, -ae (f.) | noun | freedwoman, freed person, formerly enslaved woman |
| mille (pl. millia) or M (n.) | noun | a thousand, ten hundred |
| mitto, -ere, misi, missum | verb | to send, cause to go, let go, send off, dispatch |
| mollis, -e | adjective | yielding, flexible, supple, soft, tender, delicate, gentle, mild, pleasant |
| notus, -a, -um | adjective | known, well known |
| paene | adverb | nearly, almost; mostly |
| par, paris | adjective | equal |
| patrona, -ae (f.) | noun | protectress, patroness, female patron |
| paucus, -a, -um | adjective | few, little |
| pauper, -eris | adjective | poor, meager, unproductive; cheap, of little worth |
| perdo, -ere, -didi, -ditum | verb | to destroy, make away with, ruin, squander, throw away, waste, lose |
| pervenio, -ire, -veni, -ventum | verb | to come up, arrive, reach |
| potestas, -atis (f.) | noun | power, rule, force; strength, ability |
| princeps, -cipis (m.) | noun | first man, first person, chief, leader, ruler, emperor |
| pro | preposition | (with abl.) before, in front of, for |
| quando | adverb/conjunction | when, since, because |
| quomodo | adverb | how, in what way; just as |
| recipio, -ere, -cepi, -ceptum | verb | to take back, bring back, regain, recover; to receive, accept |
| redeo, -ire, -ii, -itum | verb | to go back, turn back, return, turn around |
| Romanus, -a, -um | adjective | of Rome, Roman |
| saeculum or seculum, -i (n.) | noun | generation, age, people of any time |
| saepe | adverb | often, oft, oftentimes, many times, frequently |
| sentio, -ire, sensi, sensum | verb | to discern by sense, feel, hear, see, perceive, be sensible of |
| sine | preposition | (with abl.) without |
| sustineo, -ere, -tinui, -tentum | verb | to hold up, hold upright, uphold, bear up, keep up, support, sustain |
| tantum | adverb | so much, so greatly; only, merely, but |
| tardus, -a, -um | adjective | slow, deliberate; late |
| tempestas, -atis (f.) | noun | storm; period of time, season, weather |
| tempto (tento), -are, -avi, -atum | verb | to handle, touch, feel; try, prove, test, attempt |
| Traianus, -i (m.) | noun (proper) | Trajan, a Roman emperor |
| -ve | enclitic | or, or if you will, or as you please |
| vel | conjunction | or; either...or (vel...vel) |
| vester, -tra, -trum | adjective | your, yours, of you (pl.) |
Vocabulary in Context
Actually Attested in 10.37/10.90
- domine — vocative singular of dominus, "my lord." Pliny uses it as a deferential address to Trajan.
- aquae ductum / ductum — "aqueduct" or "water-channel." In 10.37, the phrase identifies the failed public works project at Nicomedia.
- Nicomedenses — "the Nicomedians," the people of Nicomedia who spent money on the unfinished aqueduct.
- imperfectus adhuc omissus, destructus etiam est — "it was still unfinished, abandoned, and even demolished." The passive forms emphasize the failed state of the project without naming one guilty person.
- pecuniam male perdiderunt — "they badly wasted the money." Perdiderunt is the exact form of perdo in 10.37, meaning "squandered/wasted," not simply "destroyed."
- fontem purissimum — "a very pure spring." Pliny presents the available water source as high quality.
- perduci — "to be brought/conveyed." In 10.37, aqua debere perduci means "the water ought to be brought." In 10.90, posse perduci means "to be able to be conveyed" or "could be conveyed."
- arcuato opere — "by arched work." The phrase describes aqueduct construction using arches.
- ad plana civitatis et humilia — "to the level and low-lying parts of the city." Civitatis here means "of the city," not citizenship.
- arcus — "arches." Pliny reports that a few arches remain and can be rebuilt.
- facilius et vilius — "more easily and more cheaply." Comparative forms showing Pliny's practical administrative reasoning about construction methods.
- architectum — "architect/engineer." Pliny requests technical expertise to avoid another failure.
- mitti a te — "to be sent by you." Uses mitto in the passive infinitive, meaning Pliny needs someone dispatched by the emperor.
- saeculo tuo — "your age/era." Saeculum here means "age" or "era," referring to Trajan's reign.
- Sinopenses — "the people of Sinope," the community in 10.90 that lacks water.
- aqua deficiuntur — "they lack water." Deficiuntur is passive in form, and aqua expresses what is lacking. Translate the whole phrase idiomatically: "they are short of water" or "they lack water."
- bona et copiosa — "good and plentiful." These adjectives describe the water source.
- ab sexto decimo miliario — "from the sixteenth milestone." Miliario means "milestone"; it is connected to Roman distance measurement, but it is not the same dictionary entry as required vocabulary mille ("thousand").
- locus suspectus et mollis — "a doubtful/unstable and soft place." Suspectus agrees with locus and describes ground that may be unsafe for construction. Mollis here means "soft/unstable" ground, not its gentler senses like "tender" or "pleasant."
- recipere et sustinere opus possit — "whether it can receive and support the work." Sustinere is exact required vocabulary here, used in a physical engineering sense meaning "support" structurally.
- tantam pecuniam — "so much money." Tantam here emphasizes the scale of waste, showing how much was squandered.
- pecunia...non deerit — "money will not be lacking." Pliny assures Trajan that funding has been arranged.
Required Vocabulary Meanings in These Passages
The following list explicitly maps required vocabulary words to how they function in the assigned passages of 10.37 and 10.90:
- perdo — appears as perdiderunt in 10.37 and means "wasted/squandered," not simply "destroyed." The Nicomedians squandered public money on failed construction.
- civitas — appears as civitatis in ad plana civitatis et humilia (10.37) and means "city," not "citizenship." The water needs to reach the level parts of the city.
- facilis — appears as facilius (comparative adverb) in facilius et vilius (10.37), meaning "more easily." Pliny argues brickwork is both easier and cheaper.
- mitto — appears as mitti a te (passive infinitive) in 10.37, meaning "to be sent by you." Pliny asks the emperor to dispatch an expert.
- mollis — appears as mollis in locus suspectus et mollis (10.90), meaning "soft/unstable" ground. This is the engineering sense, not the gentler meanings like "tender" or "pleasant."
- recipio — appears as recipere in recipere et sustinere opus possit (10.90), meaning "to receive/support" the construction work physically.
- sustineo — appears as sustinere in the same phrase, meaning "to hold up, support" structurally — whether the ground can bear the weight of the aqueduct.
- tantum — appears as tantam (adjective form, accusative feminine) in tantam pecuniam (10.37), meaning "so much (money)," emphasizing the scale of waste.
- pervenio — appears as perveniat (present subjunctive) in 10.37 in the purpose clause ne tantum ad plana civitatis et humilia perveniat, meaning "so that it may not reach only the low parts of the city."
- arcus — appears in 10.37 as arcus and in the phrase arcuato opere, referring to arches and arched construction.
- saeculum — appears as saeculo tuo in 10.37, meaning "your age/era," as Pliny tells Trajan the project is worthy of his reign.
- genus — appears as hoc genus operis in 10.90, meaning "this kind of work/project."
- dominus — appears as domine (vocative) throughout both letters, meaning "my lord," Pliny's respectful address to Trajan.
- tempto — appears as temptatum erat in 10.37, meaning "had been attempted," referring to the earlier try at arched construction.
Required Review Vocabulary Not Attested Here
These words are required AP vocabulary for this unit but do not appear in these two passages. Know them for the exam, but do not force them into translation of 10.37 or 10.90:
- patrona — "patroness, female patron." Relevant to the patronage system discussed in social context.
- liberta — "freedwoman." Relevant to discussions of manumission and social status.
- Harpocras — A Greek male name that appears in other Pliny letters in this unit.
- iatraliptes — "doctor, especially one who uses massage and ointments." Appears in other Pliny letters in this unit.
- Alexandrinus — "Alexandrian." Relevant to other Pliny letters in this unit.
- leo — "lion." Know the definition; it does not relate to aqueduct administration.
- exercitus — "army." Know the definition for broader Roman context.
- beneficium — "favor, kindness." Useful for patronage discussion, but not a word to insert into the aqueduct translation unless it appears in the Latin you are translating.
- princeps / imperator — useful titles for Trajan in broader context. The exact address in these passages is domine.
- tempestas — "storm; period of time, season, weather." Know the definition for the exam; it does not appear in 10.37 or 10.90.
- quomodo — "how, in what way." Know the definition; it does not appear in these passages.
- forum — "forum, market; court of justice." Know the definition; it does not appear in these passages.
- defendo — "to defend, guard, protect." Know the definition; it does not appear in these passages.
- frustra — "in vain; for nothing." Know the definition; it does not appear in these passages.
- fortasse — "perhaps, possibly." Know the definition; it does not appear in these passages.
- pauper — "poor, meager." Know the definition; it does not appear in these passages.
- sentio — "to feel, perceive." Know the definition; it does not appear in these passages.
- redeo — "to go back, return." Know the definition; it does not appear in these passages.
- tardus — "slow, deliberate; late." Know the definition; it does not appear in these passages.
When translating the assigned Latin for 10.37 and 10.90, focus especially on words connected to public works, authority, expense, water, and civic administration. If a listed review word does not appear in the passage, know its general meaning but do not force it into your translation.
Complete Translation of 10.37
The full required text of Letter 10.37 with Latin and English translation:
Latin: In aquae ductum, domine, Nicomedenses impenderunt HS XXX CCCXVIII, qui imperfectus adhuc omissus, destructus etiam est; rursus in alium ductum erogata sunt CC. Hoc quoque relicto novo impendio est opus, ut aquam habeant, qui tantam pecuniam male perdiderunt.
English: "The Nicomedians, my lord, spent 3,318,000 sesterces on an aqueduct, which, still unfinished, has been abandoned and even demolished; again 200,000 were spent on another aqueduct. Since this also has been abandoned, new expenditure is needed so that those who have badly wasted so much money may have water."
Latin: Ipse perveni ad fontem purissimum, ex quo videtur aqua debere perduci, sicut initio temptatum erat, arcuato opere, ne tantum ad plana civitatis et humilia perveniat. Manent adhuc paucissimi arcus: possunt et erigi quidam lapide quadrato, qui ex superiore opere detractus est; aliqua pars, ut mihi videtur, testaceo opere agenda erit, id enim et facilius et vilius.
English: "I myself went to a very pure spring, from which it seems the water ought to be brought, just as had been attempted at the beginning, by arched construction, so that it may not reach only the level and low-lying parts of the city. Very few arches still remain; some can also be erected from squared stone, which has been taken down from the earlier work. Some part, as it seems to me, will have to be done with brickwork, for that is both easier and cheaper."
Latin: Sed in primis necessarium est mitti a te vel aquilegem vel architectum, ne rursus eveniat quod accidit. Ego illud unum affirmo, et utilitatem operis et pulchritudinem saeculo tuo esse dignissimam.
English: "But above all it is necessary that either a water-finder or an architect be sent by you, so that what happened may not happen again. I affirm this one thing: that both the usefulness of the work and its beauty are most worthy of your age."
Complete Translation of 10.90
The full required text of Letter 10.90 with Latin and English translation:
Latin: Sinopenses, domine, aqua deficiuntur; quae videtur et bona et copiosa ab sexto decimo miliario posse perduci.
English: "The people of Sinope, my lord, lack water; it seems that good and plentiful water could be brought from the sixteenth milestone."
Latin: Est tamen statim ab capite paulo amplius passus mille locus suspectus et mollis, quem ego interim explorari modico impendio iussi, an recipere et sustinere opus possit.
English: "There is, however, immediately from the source a place a little more than a thousand paces long that is doubtful and soft; I have ordered it to be investigated at moderate expense for the time being, to see whether it can receive and support the work."
Latin: Pecunia curantibus nobis contracta non deerit, si tu, domine, hoc genus operis et salubritati et amoenitati valde sitientis coloniae indulseris.
English: "Money, collected under our supervision, will not be lacking, if you, my lord, approve this kind of project for the health and amenity of this very thirsty colony."
Notes: Curantibus nobis means "with us taking care of it" or "under our supervision." Indulseris is future perfect in the protasis; non deerit is future in the apodosis. The protasis uses the future perfect (indulseris), and the apodosis uses the future (non deerit), expressing what will happen if Trajan approves the work.
Themes to Track
Pliny's letters to Trajan show patronage at the highest level. Pliny seeks approval, reports problems, and frames himself as careful and loyal. Trajan's replies reveal imperial oversight and the limits of provincial authority.
Also track Roman social hierarchy. References to freed people, patrons, and local communities show how public administration relied on unequal social relationships. The vocabulary of this unit — words like princeps, potestas, beneficium, patrona, liberta, dominus, and civitas — reflects these layered power dynamics. Remember the review context about enslaved people and manumission discussed above: the system of slavery, the possibility of freedom through manumission, and the resulting patron-client relationships shaped Roman society at every level.
AP Exam Connection
For contextualization questions, explain how the letter form shapes meaning. Pliny is not writing a neutral report. He is presenting himself to Trajan as a competent governor who respects the emperor's authority. His careful framing of problems — wasted money in 10.37, the need for clean water in 10.90 — is part of this self-presentation.
For translation, preserve the formal register in English. Terms of address, requests, and official formulas help communicate the relationship between writer and recipient. Pay particular attention to subjunctive constructions in indirect questions and purpose clauses, and to the way passive voice is used to describe failures without assigning blame directly.
Vocabulary
The following words are mentioned explicitly in the College Board Course and Exam Description for this topic.Term | Definition |
|---|---|
allusions | Indirect or implied references to people, literary works, or historical events that readers are expected to recognize. |
Bithynia-Pontus | A Roman province located on the southern shore of the Black Sea (in modern-day Turkey) where Pliny served as governor from 110 to 113 CE. |
clients | Individuals in Roman society who were dependent on and owed loyalty to a patron, often including formerly enslaved people after manumission. |
Emperor Trajan | Roman emperor who ruled from 98 to 117 CE and expanded the empire to its greatest territorial extent while overseeing major public building programs. |
enslaved people | Individuals held as property under Roman law with limited legal rights, often performing manual labor, domestic services, or skilled work. |
manumission | The legal process by which an enslaved person in Rome was freed and typically became a client of their former master. |
patronage | A system of mutually beneficial relationships between individuals of different power and influence levels, central to Roman culture. |
patrons | Wealthier and more powerful individuals who provided assistance such as legal defense and gifts to their clients in exchange for political support. |
Pliny the Younger | A Roman lawyer, magistrate, and letter writer (61-c. 113 CE) who served under Emperor Trajan and whose letters provide insight into Roman life and administration in the first century CE. |
political patronage | A patronage relationship based on political support and influence between individuals of different social status. |
references | Direct mentions or citations of specific people, places, events, or concepts in a text. |
Roman social norms | The established customs, behaviors, and social expectations that governed interactions and relationships in Roman society. |