![[REVOLUTIONARY WAR.] THOMSON, Charles (1729-1824). Autograph letter signed ("Chas. Thomson"), as Secretary of the Continental Congress, TO JOHN JAY, Philadelphia 7 June 1780. 1 page, 4to. WRITTEN IN CIPHER, AND PARTIALLY DECODED BY JAY. Integral address leaf, inlaid.](https://www.christies.com/img/LotImages/2011/NYR/2011_NYR_02488_0175_000(revolutionary_war_thomson_charles_autograph_letter_signed_as_secretary122759).jpg?w=1)
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[REVOLUTIONARY WAR.] THOMSON, Charles (1729-1824). Autograph letter signed ("Chas. Thomson"), as Secretary of the Continental Congress, TO JOHN JAY, Philadelphia 7 June 1780. 1 page, 4to. WRITTEN IN CIPHER, AND PARTIALLY DECODED BY JAY. Integral address leaf, inlaid.
A CODED WARTIME DISPATCH TO JOHN JAY ANNOUNCING THE FALL OF CHARESLTON, THE ARRIVAL OF FRENCH FORCES AND CHANGES IN CONGRESS. A great rarity--a letter in code to Founding Father John Jay, using a code devised by Jay and partially deciphered by him in the text. Thompson writes in a code that mixes letters and numerals (decoded words follow in [brackets]): "I recd. Your favor of 29 Feby. Would it not be convenient to count down as well as up distinguishing the former thus 186 and the latter 166. I is still in LXIV [North Carolina]. I am afraid Ompnsubyjil (Charlestown) rb [is] 13245 [gone]. There is great 1191 [change] 15288 [in] 20177 [Congress] since you left us. Upyspow [Matlack] is in for LX [Pennsylvania]. LVI [Rhode Island] has made a total change except XXXXIV [Collins]. We are waiting with anxious appreciation for 2331 [arrival] 12371 [of] 19216 [fleet] & 2731 [army] from LXX [France]. There has been an engagement in the West Indies between the two fleets, but the particulars are not yet come to hand. I shall do myself the honor of writing more fully soon..."
Jay, U. S. ambassador to Spain, devised this code once he learned that Spanish officials were opening his letters. The code consisted of arabic and roman numeral designations that Jay assigned to 138 commonly used words, 56 names of prominent American and foreign officials, the 13 states and 69 other locations. For other words Jay used Abel Boyer's English-French dictionary as a key. The coder was to add seven to the page number where the word appeared, write down the sum then underline the first, second or third numeral to indicate the column in which the word appeared, and then designate the word's position in the column by counting up from the bottom and adding 10.
A CODED WARTIME DISPATCH TO JOHN JAY ANNOUNCING THE FALL OF CHARESLTON, THE ARRIVAL OF FRENCH FORCES AND CHANGES IN CONGRESS. A great rarity--a letter in code to Founding Father John Jay, using a code devised by Jay and partially deciphered by him in the text. Thompson writes in a code that mixes letters and numerals (decoded words follow in [brackets]): "I recd. Your favor of 29 Feby. Would it not be convenient to count down as well as up distinguishing the former thus 186 and the latter 166. I is still in LXIV [North Carolina]. I am afraid Ompnsubyjil (Charlestown) rb [is] 13245 [gone]. There is great 1191 [change] 15288 [in] 20177 [Congress] since you left us. Upyspow [Matlack] is in for LX [Pennsylvania]. LVI [Rhode Island] has made a total change except XXXXIV [Collins]. We are waiting with anxious appreciation for 2331 [arrival] 12371 [of] 19216 [fleet] & 2731 [army] from LXX [France]. There has been an engagement in the West Indies between the two fleets, but the particulars are not yet come to hand. I shall do myself the honor of writing more fully soon..."
Jay, U. S. ambassador to Spain, devised this code once he learned that Spanish officials were opening his letters. The code consisted of arabic and roman numeral designations that Jay assigned to 138 commonly used words, 56 names of prominent American and foreign officials, the 13 states and 69 other locations. For other words Jay used Abel Boyer's English-French dictionary as a key. The coder was to add seven to the page number where the word appeared, write down the sum then underline the first, second or third numeral to indicate the column in which the word appeared, and then designate the word's position in the column by counting up from the bottom and adding 10.