Green’s Dictionary of Slang

draft on the pump at Aldgate n.

a bad bill of exchange.

a.1754		Fielding Essay on Character of Men in Works (1840) 647: This is such another instance of generosity as his who relieves his friend in distress by a draught on Aldgate pump*. [note] *A mercantile phrase for a bad note .
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1794		Lawyer’s & Magistrate’s Mag. III 256: What is a fictitious payee but the pump at Aldgate?
1811		Lex. Balatronicum.
1827		Morn. Chron. (London) 1 Mar. 4/1: They never would be paid, except by a draft an Aldgate pump.
[1833		Satirist (London) 7 July 5/3: [of actual water] I would [...] advise you to sharpen your faculties by a dolphin-like draught from the pump at Aldgate].
[1836		Bell’s Wkly Messenger 11 Dec. 398/1: She vas as firm as the pump at Aldgate].
1838		R.S. Surtees Jorrocks Jaunts (1874) 170: I’ll give you a draft on Aldgate pump for the amount.
1846		Thackeray Diary of C. Jeames de la Pluche in Works III (1898) 387: Having received a cheque for the amount (on Messrs. Pump and Aldgate, our bankers) tears came into the honest fellow’s eyes.
1853		Western Times 10 Sept. 6/4: I suppose the term ‘a cheque on Tawstock Bank’ in Barnstaple was equivalent to the phrase, ‘a draft on Aldgate pump’ in London.
1862		E. de la Bédollière Londres et les Anglais 314/1: draught on the pump at aldgate [...] fausse lettre de change.
1868		Leamington Spa Courier 25 Apr. 7/2: Joyce [...] tendered to witness what he said was a bank note but which [...] proved to be a note on ‘the bank of elegance’, and about as good security as ‘a draft on the Aldgate pump’.
1873		Sl. Dict. 149: Draft on Aldgate Pump, an old mercantile phrase for a fictitious banknote or fraudulent bill.
1900		Star (London) 11 Oct. 4/2: A ‘draft on Aldgate pump’ was, according to Fielding, a mercantile phrase for a bad note.