Thomas Jefferson Papers

Enclosure: William J. Coffee’s Memorandum to Thomas Jefferson on Roman Cement, [ca. 7 November 1818]


William J. Coffee’s Memorandum on Roman Cement

[ca. 7 Nov. 1818]

notes on the Roman Cement

This Cement is not A Composition It is A natural production of A Very Extraodinary Kind I think it is Very Common in this Country, and Som future time I shall troubl you to Asist me in finding it out as I well understand the maner of manufatre and Application, and tharefor my Observations to you as to the maner of usesing it may be depended on

All the new and fashionably Houses have Cistren made of this Cement and in Som Cases the outsids Are decorated it is now coming in to Vouge in this City Vere fast. It has also being used to Stop Out the back waters from Buildings and in One Instans to Stop out the back water from mixing with the water of A wood Cistern in Boath Cases with Every Success. The Price of this Cement is $9 pr Barrel of five Bushels in Each Barrel as you will see When we Consider the hight price of prepared Plaster which is as much as from 7 to 8$ pr Barrel of five bushels we cant think much of 9$ for wat is so usefull and from so distant a Clime

I have Inclosed a printed Card so that you will know ware to Aply to should you make up you mind to use it I have also Sent you two or three Specimens of the Cement as Imported so that you may try in som mesur in you Study before you giv an Order One of thease Specimens marked I got from out of A Barrel Just Opened in The Public Store for Inspection this you know must be Considerd a fair trial thare are now as pr Advertisement sent you 20 Barrels no doubt all good Tho the Season in you Country A fine One for The Operation If Immeaditly taken hold of other ways you had better to Stay till April or the Last week in march, in this Case you Can hav If you give you Immiadet Order to the manufactory in London wat you may want Sent direct to Richmond the other Specimen I had out of A Barrel that had being on Headed fer Som day & not minded in the maner it should be as it was the remains of wat was left in the making of A Cisterns in mury St, Built by A mr maybe Builder of new York. its not so good it is mark’d The litle Cistern is made of it yet I think this in its present State would do provided it was well Lay on the Brickwork I Only mention becaus you might hav A Barrel thus exposed to the Common Air, thease Specimens I shall send off by the Ship to Richmond to the Care of Capt Peyton to be Sent to you as soon a Possable


As to the Thickness in new York The workmen Lay it on, from half to ¾ of Inch, but I Should Say, not Less then from ¾ of Inch to One Inch—in Short the thicker it the mor you are Sur of Success previous to the Laying on the Cemnt Let you walls & Bottom be well Cleaned from dirt of all kinds and the morter from the Joints take out also the Present Clay and Sand or wat may be at the bottom of you Cistern, that don Let thar be a Large Squar Bored 2 Feet by 6 Strond and Smooth on One Side Let One Cask of Cement be roled to the top of you Cistern and opt it Place the Squar Board in the bottom of Cistern then Let the Attendant or the mason take out of this Barrel half A Peck Only at a tim and Place it on the Board below, Place this half Peck in the form A Cone, from the Point of which make an Eaqul Concavity to the Board Put in to this no more water [which ought to be Very Clean]1 then will make the Cement in to that Consistance of dough to bake for Bread, for If the man Should over water the mixing in Ever so small a dgree so in Proposition would the Cement be Injured ontill the division would be so gread as to Concretion which If Properly attended will be allmost as Hard a Common Stone.   I Should recommend the mason Cover One half of Each End at Side of Cistern thinly at first Say ¼ Inch this Should be well Troweld or rubed in, to the bricks but allways taking the greatest Care not to tuch the Cemnt any Longer then is necessary to give it adherence this requires Som address—for If you mix up Som of this Cemnt very Stiff Leave it to Set and not tuch it ontill it is hard you will find this harder then that from the hands of the workman,

On this thin Coat Let him Place in the Same maner his Last & finishing Coat which ought to be Just floated down with a rule and never tuch with the Trowel, but Left to Set in this way he gos on ontill he has Complete the whole, but you must mind that he maks Sound Joining & Angles that no Air may Caus a Crack which would Spoil all.

The Bottom I think I would finish the Last on A[ccount?] of Likelyhood to Injury it ought to be Composed of well [. . .] layed or wat is Caled beded in this Roman Cement in the [. . .] of morter and on that bottom Lay your Coat of Roman Cemnt at Least One Imch in thickness begining at the ferthermost Part of the Cistern and working backwards. not Suffer any pressure on the bottom ontill it has becom Quite harde that may be in A day or two at which End of time If you Can Conviently fill you Cistern with water or Let a Small2 Boy get in and fling water over the whole this will much asist. in a few days from that time it asume a moldy Look which is A sign of its goodness—I fear by this time you will be very glad my Small sheet of paper is allmost full of any thing you Like to Call it you hav brought it on you self and then cant blame me. and I Conclude by saying that If you think you Cand do this business so well as you Could wish I will Inspect it for you in next march on my route as I do Intend call and Look at monciello Once again my Only reward for two or three days Inspection will be two glasss of good wine Every day affter diner ontill then If you want my Services in New York you may Command them and I shall with Pleasur be conformabe to you wish

The End

MS (DLC: TJ Papers, 214:38126–7); entirely in Coffee’s hand; undated; torn at seal; subjoined to covering letter. Enclosure not found. Also enclosed in TJ to John Brockenbrough, 4 June 1823, and Brockenbrough to TJ, 16 June 1823.

An unheaded (on headed) barrel has had its closing lid removed (OED description begins James A. H. Murray, J. A. Simpson, E. S. C. Weiner, and others, eds., The Oxford English Dictionary, 2d ed., 1989, 20 vols. description ends ).

1Brackets in original.

2Word interlined.

Index Entries

  • cement; Roman search
  • cisterns; in New York City search
  • Coffee, William John; and cement for TJ search
  • Coffee, William John; Memorandum on Roman Cement search
  • Coffee, William John; visits Monticello search
  • Great Britain; cement from search
  • Maybie, Abraham P.; as builder search
  • Monticello (TJ’s Albemarle Co. estate); Visitors to; Coffee, William J. search
  • Peyton, Bernard; and goods for TJ search
  • wine; served at Monticello search