但是要想建造一台实际的蒸汽机还有很长的路要走。首先是资金,布莱克教授提供了一些帮助,但更多的资助来自于约翰·罗巴克。罗巴克是一位成功的企业家,著名的卡伦钢铁厂(英语:Carron Iron Works)的拥有者,在罗巴克的赞助下,瓦特开始了新式蒸汽机的试制,并成为新公司的合伙人。试制中的主要困难还在于活塞与气缸的加工制造工艺上。当时的工艺水平下钢铁工人更像是铁匠而不是机械师,所以制造的结果很不满意。此外由于当时的相关专利申请需要国会的认可,大部分的资金都花费在相关程序上。由于资金的短缺,瓦特不得不另找了一份运河测量员的工作,并一幹就是8年。[15]这之后,罗巴克破产,相关专利都由伯明翰一间铸造厂老板马修·博尔顿接手。瓦特与博尔顿从此开始了他们之间长达25年的成功合作。
^Although a number of otherwise reputable sources give his date of death as 19 August 1819, all contemporary accounts report him dying on 25 August and being buried on 2 September. The date 19 August originates from the biography The Life of James Watt (1858, p. 521) by James Patrick Muirhead. It draws its (supposed) legitimacy from the fact that Muirhead was a nephew of Watt and therefore should have been well-informed. In the Muirhead papers, 25 August date is mentioned elsewhere. The latter date is also given in contemporary newspaper reports (for example, page 3 of The Times of 28 August) as well as by an abstract of and codicil to Watt's last will. (In the pertinent burial register of St. Mary's Church (Birmingham-Handsworth) Watt's date of death is not mentioned.)
^Henry Winram Dickinson; Rhys Jenkins; Committee of the Watt Centenary Commemoration. James Watt and the steam engine: the memorial volume prepared for the Committee of the Watt centenary commemoration at Birmingham 1919. Clarendon press. 1927: 78. It is difficult to say anything as to Watt's religious belief, further than that he was a Deist.使用|accessdate=需要含有|url= (帮助)
^Joseph McCabe. A Biographical Dictionary of Ancient, Medieval, and Modern Freethinkers. Haldeman-Julius Publications. 1945 [17 August 2012]. (原始内容存档于2013-03-23). He made such improvement in the crude steam-engine that had been invented before his time that he is usually described as the inventor. "His many and most valuable inventions must always place him among the leading benefactors of mankind," says the account of him in the Dictionary of National Biography. He was an accomplished man. He knew Greek, Latin, French, German and Italian and was very friendly with the great freethinking French scientists. Andrew Carnegie has written a life of him and describes him as a deist who never went to church.
^Tann, Jennifer. James Watt (1736–1819). Oxford Dictionary of National Biography. Oxford, England: Oxford University Press. 2004.
^Thomas, Henry; Thomas, Dana Lee. Living adventures in science. Ayer Publishing. 1954: 25.
Dickinson, H. W. and Hugh Pembroke VowlesJames Watt and the Industrial Revolution(published in 1943, new edition 1948 and reprinted in 1949. Also published in Spanish and Portuguese (1944) by the British Council)
Hills, Rev. Dr. Richard L., James Watt, Vol 1, His time in Scotland, 1736-1774 (2002); Vol 2, The years of toil, 1775-1785; Vol 3 Triumph through adversity 1785-1819. Landmark Publishing Ltd, ISBN 978-1-84306-045-1.